How to play for a draw?

If you're in a situation where you need a draw, how should you play differently than a normal game?

First of all unless you're a master level player you shouldn't be playing for a draw - that's a sure way to lose, the fact is that anyone below master strength will make too many errors to be able to afford to play passively. 

Having said that, if you do only need half a point, you still want to play for a win but avoid unecessary risks that you might take in a normal game depending on the type of player you are.  For example, don't sacrifice material unless you can see a concrete variation where you will either win it back or give mate, don't play into king race type positions etc...

The biggest mistake you could do is to avoid your usual openings in favour of some "drawish" line you're unfamiliar with.

In the middlegame, it's ok to avoid risks, provided that you don't compromise your position just to avoid complications. There are situations in every game where there are several good moves to chose from; there you can go for the safe option.