How do I make clearer beer?

Answer 1

One issue is style of beer, some beers are meant to be cloudy.  So you'll want to pick lower protein grains.
 
I've used Irish Moss, Super Moss or like near the end of the boil. This types of adjuncts help the proteins to flocculate or clump together and drop out of the liquid.  

Along with Irish Moss I also try to cool the wort quickly.  There are different methods to accomplish this.  I use an immersion chiller that I pump ice water through.  Dropping down to pitching temp within 15-20 is best.

Another method is to use a high flocculating yeast.  The higher the rate the faster the yeast will drop out of the liquid.  Again,this is preferred in some beer styles.
 
Another method I've heard of, but haven't tried yet, is the use of a fining agents.  There are some name brand agents you can buy at your LHBS or you can try is clear, plain gelatin from the grocery store. Follow in the packet instructions and add it to your secondary fermenter, in your keg or few days before bottling.
 
Lastly I'd say time and temperature. The longer and colder you can refrigerate your beer the better, but don't let it freeze! Also, if you're bottle conditioning, don't refrigerate it before your carbonation process has taken place or you'll wind up with under carbonated beer.  If that happens, let the bottles warm up to room temperature for a week or so and refrigerate.