I used to use splits, then I used tabs + splits, now I just use buffers. The only time splits come into it are for quickfix or diffs. Just get used to buffers. Lots of vim commands will work with buffers but not with splits or tabs.

People new to vim will immediately jump on splits or tabs because of how their previous editor work flow worked, but you aren't going to unlock the full power of vim until you get used to buffers.

:b# last buffer used

:b num Switch to various buffers by number

:buffers See a list of buffers

:bd delete buffer

^^ map those to keys

cntrlp for easy buffer switching and opening: https://github.com/kien/ctrlp.vim