I have the key sequence jk mapped to Esc.
You might ask, so what happens when you come across a word with jk. No problem. Type j, wait for half a second and then type k. Yes, that's non-ideal but the advantages of not having to move your hands of home row is much more.
I highly recommend jk sequence as `Esc.
Other variations of the same idea are jj - which in my humble opinion wont work for me. I use j for moving down - as others.