After a good defense, you should be in a position to attack.  The vital aspect of this is the transition, moving from defense to attack.  You cannot give the opponent time to recover from your defense. 

One of the most effective ways to do this is a few quick strikes.  Technique is not as important as keeping the opponent in a defensive position here.  So, a fancy time consuming technique is disasterous here.

The best method of attack is a target oriented one.  Instead of worrying about a perfect technique, you should focus on hitting a vital target.  Here is a list of some of the best targets:
-temple of the head
-eyes
-nose
-side of the jaw
-carodit arteries
-throat
-solarplex
-groin
-knees

Notice that most of the targets are above the shoulders and below the waist.  So, throwing a few strikes to the head area and then moving directly to a few low line kicks will be very effective.

The main thing you want to do here is get the opponent moving backwards, which keeps them in a defensive position.  So remember, quick strikes to vital targets are more effective than a perfectly thrown technique.

And one more thing,  do not focus on perfectly hitting the targets either.  A quick hit will make your opponent move back whether you hit the target or not.  The best thing to do is:  throw about 3 strikes to the head, then three low kicks to the legs.