Creating a vimrc is the first step vimrc. Writing ftplugin/*.vim files is the next (configure vim for some filetypes only).
Such mapping can be helpful which opens the filetype specific file corresponding to whatever you're editing right now:
noremap \ft :exec 'e ~/.vim/after/ftplugin/'.&filetype.'_you.vim'<cr>
If you need more control you can try auto commands like this:
augroup YOUR_PROJECT au! autocmd BufRead,BufNewFile PATH_TO_YOUR_PROJECT/**/*.c set sw=2 augroup end
project local settings: see local-vimrc
per file: see modeline