Set ups and reads are a massive part of fighting, as they can be used to make decisions on the openings they create.
When setting up a question mark kick, you should first strike low with your kicks, watching to see if the opponents same side hand reaches down instead of checking the kick.
If you see them reach, then you know you have an opening to deceptively throw the question mark kick. Another option is also our superman punch to high kick combo.
Raising your knee in the same way as a normal low kick will bring their hand down, from here you can take advantage of the opening you have created and turn your hip over mid kick and kick them in the face.
The most important part of a question mark kick is the set up and your range. If you do not set the kick up properly, then the opponents hand will be in the way of his face, taking away your opening.
If you are in the incorrect range, then you will wiff on the kick, missing it by inches. It is important to remember that the range of a question mark kick is actually closer than a regular head kick.
This is because you have to lean back hard on a question mark kick after your knee comes up so that you can turn your kick over.
For more in depth analysis check out The Ultimate Guide to Striking for MMA, Muay Thai and Kickboxing.