When you serve, return serve, or hit any shot throughout a table tennis match, your opponent will have a variety of choices on how to return the ball.  You need to prepare yourself for the worst-case-scenario then adjust if he does something easier.
 
For example, if you serve short topspin, then prepare for a fast flip.  Get ready.  Know what you will do if he gives you the difficult return.  If he misses your serve, great!  If he gives a high push, great!  If he flips soft, great!  The same applies with any shot.  Instead of hoping that you will surprise him, expect the worst and keep your eyes open for anything else!