I really enjoy vim tabs for multiple files. Especially if I don't need to see all of them at once, but just quickly switch between them. `:tabnew foo.txt` to open another file, then `gt` to go to the next tab and `gT` to go back.

If you work interactively with data, you might also enjoy Slimux (https://github.com/epeli/slimux), a vim plugin that allows you to send lines from vim to an arbitrary tmux pane. I usually have IPython running in such a pane so I never have to copy+paste. I've got an ebook I've been kicking around describing this workflow in more detail here (http://dvbuntu.github.io/compute/posts/2050/01/01/workflow.h...).