Remote desktop Linux to Linux

Trying to get this to work but all the instructions I can find are hopelessly obsolete and useless. I use Remmina to connect from my Linux box to Windows and it works without issues and was simple to set up. Not so Linux. If someone could point me to current instructions I would be most grateful. I don't really care what protocol I use as long as it works. I would prefer to use Remmina as I'm familiar with it.