A few things I wish I'd done as soon as I started with Vim

.vimrc

" relative linenumber. very helpful for "8yy"-style operations
set relativenumber

" once you get used to virtualedit=all, it's so great
set virtualedit=all

" setting this allows you to undo into previous sessions, all the way back to the start of a file 
" (providing the path hasn't changed). 
" very useful with the Vundle plugin
set undofile
set undodir=~/.vim/tmp/undo//

" keep your swp files out of working directories
" (remember to actually MAKE these dirs before setting this)
set backupdir=~/.vim/tmp/backup//
set directory=~/.vim/tmp/swap//

" quick project-search shortcut
nmap <leader>g :vimgrep // **/*.*<left><left><left><left><left><left><left><left>