So, the deed is done and the world is topsy-turvy. Take a long break before you speak to your ex again. Three weeks is the absolute minimum time you need to gather your thoughts and emotions. (Ideally you won't speak to them again until you're married, to someone else, with two children. But that might be impractical.)
Don't bother to put on a brave face – you're just storing up problems for later. Be as depressed and hysterical as possible until it gets boring. Only then can you put yourself back together.
Don't play dirty
There's nothing more personal than a break-up, so don't make it even worse. Spreading rumours – about performance in bed, drug-taking, rows where you were sure he was close to taking a swing at you – only ever results in horror stories coming from the other side. And just when you are least expecting it.
Revenge isn't cool
OK, so she dumped you by text to go out with the boy you sat her next to at your last birthday party. But, however cleverly executed it is, revenge-taking always looks crazy and you will cringe about it later. The best way to get your own back is to find happiness elsewhere.
Beware the rebound
Make sure you avoid a very public rebound. Like so much in life, it doesn't matter what it is, it matters what it looks like. Leaping into the trousers of the nearest person after a split and making sure that it gets back to your ex will hand them, on a silver platter, licence to tell everyone that you are "having trouble getting over it" and "in a mess". That's just bad PR. By all means do a rebound, but be subtle about it.
Moving on doesn't necessarily mean going out with someone else. Use a break-up as an excuse to have a bit of a spring-clean. Sort out that towering stack of paperwork, get that picture fixed, quit your job, move house – whatever. Change and improve things you're unhappy about and you'll feel more in control of your life – and it will help to reduce any lingering bitterness about the split.
Sometimes the only thing that can make you feel better is to blame a higher power; believe in fate, if only briefly, and tell yourself you were supposed to split up so that you can meet someone who doesn't leave the milk out, hair in the basin and you for the plumber.