The one thing you can do to try to ensure clear beer is to not transfer trub from the primary to the secondary and then to your bottle/keg.
Too many time people will try to transfer 100% of their brew. I always recommend making 1/4 - 1/2 gal extra for this loss.
Other than that you can use Irish Moss in the boil or Polyclar, Isinglass, Gelatin or Finings in the secondary.