Customizing tmux and making it less dreadful

I have been exploring some new tools here and there. When I started watching Primeagen, I took a note of several tools that he was using and advocating for. One of them was tmux.
What is tmux? tmux is a terminal multiplexer. What that means is you can have many terminals in one. According to tmux wiki:
tmux is a program which runs in a terminal and allows multiple other terminal programs to be run inside it. Each program inside tmux gets its own terminal managed by tmux, which can be accessed from the single terminal where tmux is running - this called multiplexing and tmux is a terminal multiplexer.