When you are declarer, try to figure out what the opening lead means.

Before you play to the first trick, analyze the opening lead.  Does it
help you to place even one other card?  If LHO leads a suit his partner
has bid, what message is he trying to send to partner about his holding?

This is the first step in determining how you are going to play the hand.
More contracts are lost at trick one than at any other time.  Take a 
moment and do the work you know you want to do!