A couple of tricks I have my trainees do:
1. Stand on one leg (heel Off floor), hook opposite foot behind standing leg knee. Flex standing leg's knee. Simulate the kick movement with the rest of the body with foot hooked behind knee. Pivot and twist the body same as kicking and then pivot back to forward position. Work to pivot the standing foot 180 degrees and back. This exercise will help strengthen the pivot, the standing leg & foot and help the recovery of the kick action.
2. You need a partner for this. Every part of this exercise is important. This exercise is done slowly and no power.
The kicker slowly performs the kick placing the kicking leg on the partners ribs while performing All of the kick action with the body. (pivoting the opposite foot 180degs. with heel up off floor, Shoulder to chin, kicking leg knee slightly below the ankle, kicking side arm drops to behind kicking leg hip...) Partner catches and holds the leg assuring the kicker's position is correct. The last action the kicker thrust the kick leg hip forward into the kick. As this is done the partner pushes the kick leg away and the kicker recovers the kick. The Push by the partner is very important to the kick recovery process.
At first the kicker will be unstable and have a hard time holding the kick position as well as recovering the kick. Especially if the the partner pushes hard. However, this exercise will help the kicker become a rather proficient kicker in a very short time. I find using this process most beginners are able to perform kicks with power and recover them functionally within four training sessions. I have them do 25 of these each session on each leg then just have them kick. They finish each session with 15 of these again each leg. After that simply kick and kick, kick, kick...