I direct sowed yesterday. I've never grown lettuce before, tried last year and the seedlings got nommed by slugs after starting well.
I watered the soil, made a drill, filled that with water, let it drain, sowed far too many seeds probably, covered them, watered them gently (so they didn't wash away) and put a plastic cloche over them (mainly to keep leaf miners off the beetroot seedlings that were planted next to them).
Apparently they're more prone to bolting in warmer weather, especially if not kept watered. I'm looking forward to seeing what happens.