What is your favourite way to transfer files in your homelab?

sftp
All my machines have my keys, nothing to set up, nothing to tear down.

Snapdrop if they both have a gui/webbrowser. https://github.com/SnapDrop/snapdrop
Scp otherwise

rsync -are ssh from to@pc:/dir

rsync over an SMB share was pretty seamless.

you can use a regular ftp server with administrator and user rights, distribute rights to those who replenish, and those who just take - guests at home I transfer in this way from computer to computer without connecting them to a common network, what could be simpler? why invent some ways with keys or bash if there is a 40-year-old technology that just works great, and to open ftp it is enough to enter the IP address in the explorer

What's wrong with rsync? If you don't like IP addresses, use a domain name. If you use certificate authentication, you can tab complete the folders. It's a really nice UX IMO.
If you'll do this a lot, just mount the target directory with sshfs or NFS. Then use rsync or a GUI file manager.
- Just don't run rsync as a daemon as that's a security nightmare
  
  Why would you do that? That sounds awful...
- I never even set up DNS for things that aren't public facing. I just keep /etc/hosts updated everywhere and ssh/scp/rsync things around using their non-fqdn hostnames.
  
  You could also use mDNS to the same effect.

What do you mean by specifying IP address?

Not gonna lie, I just map a network share and copy and paste through the gui.
- Yeah, I mean I do still use rsync for the stuff that would take a long time, but for one-off file movement I just use a mounted network drive in the normal file browser, including on Windows and MacOS machines.
- Same lol, somebody please enlighten me on a faster way!
- Sounds very straight forward. Do you have a samba docker container running on your server or how do you do that?
  
  I just type sftp://[ip, domain or SSH alias] into my file manager and browse it as a regular folder
  
  Do you really need a container for Samba?
  I see the benefits of containers, but a use would be overkill.
  
  I have two servers, one Mac and one Windows. For the Mac I just map directly to the smb share, for the Windows it's a standard network share. My desktop runs Linux and connects to both with ease.
  
  Set up smb on my file share VM.
  My dedicated docker host accesses it through an NFS mount.
  
  I dont have a docker container, I just have Samba running on the server itself.
  I do have an owncloud container running, which is mapped to a directory. And I have that shared out through samba so I can access it through my file manager. But that's unnecessary because owncloud is kind of trash.

Ähm. So your not gonna like this but I just connect with vscode remote-ssh and drag'n drop em from the os file explorer into the vscode one.
So long story short scp I guess.

People have already covered most of the tools I typically use, but one I haven't seen listed yet that is sometimes convenient is python3 -m http.server which runs a small web server that shares whatever is in the directory you launched it from. I've used that to download files onto my phone before when I didn't have the right USB cables/adapters handy as well as for getting data out of VMs when I didn't want to bother setting up something more complex.
- Honestly, this is an easy way to share files with non-technical people in the outside world, too. Just open up a port for that very specific purpose, send the link to your friend, watch the one file get downloaded, and then close the port and turn off the http server.
  It's technically not very secure, so it's a bad idea to leave that unattended, but you can always encrypt a zip file to send it and let that file level encryption kinda make up for lack of network level encryption. And as a one-off thing, you should close up your firewall/port forwarding when you're done.

Just regular old WinSCP, or XPipe for smaller stuff and editing config files.
I need a GUI, I'll use rsync to migrate a lot of data to a new server or something occasionally, but it's just a pain compared to a nice graphical file browser.

scp
- Checks username… yeah that tracks
- scp is deprecated.
  
  SCP, the protocol, is deprecated. scp, the command, just uses the SFTP protocol these days. I find its syntax convenient.

I like unison personally. It is a bit more of a hassle but it works pretty well.

Rsync and NFS for me.
- And me.

Syncthing

smb share if its desktop to desktop. If its from phone to PC, I throw it on nextcloud on the phone, then grab it from the web ui on pc.
Smb is the way to go if you have identity set up, since your PC auth will carry over for the connection to the smb share. Nextcloud will be less typing if not since you can just have persistent auth on the app / web.
- Solid explorer on android is pretty useful too, it can access the SMB share. I use nextcloud for photo backup, but usually solid explorer for one off file transfers.

rsync over ssh or scp.

rsync is indeed fiddly. Consider SFTP in your GUI of choice. I mount the folder I need in my file browser and grab the files I need. No terminal needed and I can put the folders as favorites in the side bar.
- If you want to use the terminal though, there is scp which is supported on both windows and Linux.
  Its just scp [file to copy] [username]@[server IP]:[remote location]
  
  That's essentially the same as rsync

sftp for quick shit like config files off a random server because its easy and is on by default with sshd in most distros
rsync for big one-time moves
smb for client-facing network shares
NFS for SAN usage (mostly storage for virtual machines)

rclone. I have a few helper functions;
elvish

fn mount { rclone mount http: X: --network-mode } fn kdrama {|x| rclone --multi-thread-streams=8 --checkers=2 --transfers=2 --ignore-existing --progress copy http:$x nas:Media/KDrama/$x --filter-from ~/.config/filter.txt } fn tv {|x| rclone --multi-thread-streams=8 --checkers=2 --transfers=2 --ignore-existing --progress copy http:$x nas:Media/TV/$x --filter-from ~/.config/filter.txt } fn downloads {|x| rclone --multi-thread-streams=8 --checkers=2 --transfers=2 --ignore-existing --progress copy http:$x nas:Media/Downloads/$x --filter-from ~/.config/filter.txt }
So I download something to my seedbox, then use rclone lsd http: to get the exact name of the folder/files, and run tv "filename" and it runs my function. Pulls all the files (based on filter.txt) using multiple threads to the correct folder on my NAS. Works great, and maxes out my connection.

WinSCP for editing server config
Rsync for manual transfers over slow connections
ZFS send/receive for what it was meant for
Samba for everything else that involves mounting on clients or other servers.

Magic wormhole is pretty dead simple https://magic-wormhole.readthedocs.io/en/latest/welcome.html#installation
I use this a lot at work for moving stuff between different test vms, as you don't need to check IPs/hostnames
- As I understand it, the establishing of the connection is reliant on a relay server. So this would not work on a local network without a relay server and would, by default, try to reach a server on the internet to make connections.

As a lazy person, I just prefer sftp on thunar.

By "homelab", do you mean your local network? I tend to use shared folders, kdeconnect, or WebDAV.
I like WebDAV, which i can activate on Android with DavX5 and Material Files, and i use it for Joplin.
Nice thing about this setup is that i also have a certificate secured OpenVPN, so in a pinch i can access it all remotely when necessary by activating that vpn, then disconnecting.

Ye old samba share.
But I do like using Nextcloud. I use it for syncing my video projects so I can pick up where I left off on another computer.
- Samba Bamba!!

Syncthing and/or ftp.

I'd say use something like zeroconf(?) for local computer names. Or give them names in either your dns forwarder (router), hosts file or ssh config. Along with shell autocompletion, that might do the job. I use scp, rsync and I have a NFS share on the NAS and some bookmarks in Gnome's file manager, so i just click on that or type in scp or rsync with the target computer's name.

rsync if it's a from/to I don't need very often
More common transfer locations are done via NFS

I work from home, however my two systems (home and work) are on the same LAN, they don't see each other for file sharing. I get paid via direct deposit like everyone else which means my pay stubs are all electronic. I print those out and then use WinSCP to copy those over to my desktop. No other files are ever sent.
At home, depending on the amount of files, I either use SFTP via Filezilla, or if the mood strikes me and for a single file, I will just use SCP if I'm already on the cli which is most of the time it seems anymore doing work on my personal servers. I've found that SFTP is faster at transferring than doing a copy/paste to the NFS share to the same drive.

Resilion Sync

I have a shared syncthing folder on all my devices
- A single folder synced between all of them, or a separate folder for each, syncing everything to a single device?
  
  The first, single folder for all of them.

SFTP! 😃

Depends on what I'm transferring and to/from where:
scp is my go-to since I'm a Linux household and have SSH keys setup and LDAP SSO as a fallback
sshfs if I'm too lazy to connect via SMB/NFS (or I don't feel like installing the tools for them) or I'm traversing a WAN
rsync for bulk transfer and backups
Snapdrop/Pairdrop for one-off file/text shares between devices with GUIs (mostly phone <--> PC)
SMB if I'm on a client PC and need to work with the files directly from the fileserver
NFS between servers
To get bulk data to my phone (e.g. updating my music library), I connect via USB in MTP mode and copy from the server via SMB or sshfs.