Well the mistake not to make is to rush out and try and get back into a relationship and make things 'as they were'.
That was the mistake I made. 13 women in 11 months and I lived with one for four of those.
Problem is you're still angry and you're not over it and as soon as they do one thing to remind you of the last you'll rid of them. Still, the shagging was fun and I didn't even catch any incurable diseases (apart from glandular fever which sucked).