After years of abusing my little finger for using Ctrl & the RSI that goes with it, I tend to use alt/meta with my thumb more and more nowadays, for this I make it usable in insert mode also, this is probably one of the oldest bits of my .vimrc

    "quick window movements
    map <a-w>  <c-w>
    map <a-l> <c-w>l
    map <a-k> <c-w>k
    map <a-j> <c-w>j
    map <a-h> <c-w>h
    imap <a-l> <esc><c-w>li
    imap <a-k> <esc><c-w>ki
    imap <a-j> <esc><c-w>ji
    imap <a-h> <esc><c-w>hi