It's wise to approach a match with the idea of using your strengths, but don't forget to test your opponent as well. You don't want to lose a match because you didn't find a glaring weakness in your opponent's game! Often you can win a match by matching your weakness against an opponent's even bigger weakness. So test your opponents – serve long & short, test their forehand, loop at different speeds, try pushing, etc. Don't risk not knowing your opponent's weaknesses!