For switching quickly between the 10 most recently used buffers:
I suggest adding this to your .vimrc (the default mapping is <Leader>lj; my leader key is the spacebar, and I find space space to be much better):
let g:LustyJugglerDefaultMappings = 0
nnoremap <silent> <Leader><Leader> :LustyJuggler<CR>
For very quickly jumping between the current buffer, and the last buffer I have a mapping:
nnoremap <leader>dd <C-^>
because <C-^> is a bit awkward; <leader>dd could be anything that's very easy to type.
So most of the time I'm alternating between two files using the <C-^> mapping. When I need to jump to a less recently used buffer I double tap <space>, opening LustyJuggler, then double tap the appropriate home row key to jump to the buffer I want. If the buffer I want isn't in the ten most recently used, I open Ctrl-P, type enough characters from the file path of the file I want to make it the first choice, then hit enter.