The default keybinding for copy-mode <prefix>-[ is one that is just so awkward for me to hit that I end up not using it at all. I was on a call with my buddy Nic this week and saw him just fluidly jump into copy-mode in an effortless fashion, so I had to ask him for his keybinding and it just made sense. Enter, that's it. So I have addedt his to my ~/.tmux.conf along with one for alt-enter and have found myself using it way more so far.

Setting copy-mode to enter

To do this I just popped open my ~/.tmux.conf and added the following. Now I can get to copy-mode with <prefix>-Enter which is control-b Enter, or alt-enter.

bind Enter copy-mode
bind -n M-Enter copy-mode

More on copy-mode

I have a full video on copy-mode you can find here.