Another excellent trick I read somewhere is to map 'jj' or 'jk' to esc when in insert mode (so 'inoremap jj <ESC>'). As a digraph they never occur in a natural language, so you'll never type it accidentally. And you can hit it on the home row easy-peasy.

Although personally I type in Colemak, I still use this, just with 'yy' instead. To be honest, it's a barely noticeable slow-down but it's much less stressful for my hands.

There are really a lot of ways to do this. See: http://vim.wikia.com/wiki/Avoid_the_escape_key