Make sure that you are in fact ready to date again.
Have you really moved on from the past? You should not re-enter the dating scene if you are still feeling jaded from the abandonment or rejection from your last relationship.
Give yourself time to really heal.
After a long relationship, it usually takes about a year (on average) to recover.
Only when you have settled all the legal and financial aspects (in the case of divorce, for example) can you really say that you are ready to date again.
Date because YOU want to date, not because someone else told you that you should.
Friends - as well meaning as they are - sometimes put undue pressure on you to date again even when you're not ready.
So ask yourself - what is your motive? Are you just so lonely that you are willing to go out with any random dude? Perhaps you are just feeling vulnerable? You cannot rely on the next man who comes along to settle those issues for you.
Make sure you get your act together first before you even date.
Explore online dating.
If you're feeling a bit rusty, try online dating first.
There you can easily see like-minded adults with similar interests and circumstances as yours.
It's also a great chance to see what's out there, so you know what to expect.
If you meet someone you like, send an email or two, and flirt casually online.
That way, you can practice.