Hop Ga kicks: applications
Here's one for training endurance and balance:
Start with left leg in front. Do a forward daan geuk as a front slap kick (paak). Go for as much height and speed as you can get. As you drop the kicking foot into a front gung jin bouh, perform the same kick on the left side. As the left foot lands, jump into a butterfly kick while clearing with a right gaau sau or "stirring hand." (This is the same as Choy Lei Faht's poon kiuh). You sweep the space in front of you just before the right foot comes up the center to start the butterfly. As the right foot retracts, the left does the same kick but meets the left hand in a paak geuk. As the left foot touches down, jump off of it to perform clockwise syuhn fung teui at least three times in quick succession or keep going until you run out of room. When you get to the end of the hall, turn and repeat the series going back, this time starting with the right foot in front so the whirlwind kicks go counterclockwise.
Try to keep your road straight. Beginners usually get dizzy a little way into the exercise. With time, your body adapts and you can keep up the spinning kicks for longer periods.
We used to practice this with every kicking session. When completed we were warmed up enough to do more strenuous kicking drills.
In a similar manner you can do sou geuk foot sweeps across the floor by alternately sweeping with the shin of one foot and the heel of the other, going clockwise in one direction and counterclockwise in the other.