i do it by doind a burst shot (takes pics straight after each other, each one has a different shutter speed so it will take closer together videos) make sure the camera is on a tripod though to keep the same area in the shot, then with the photos go onto an editing software (i use paint ) and open an original main image, for example the one of him on the take off in it and open it, then go to the other photos and crop around the rider leaving just a small photo of him. then paste this cut down image onto the original main photo and pste it then fit it in like a jigzaw to its surroundings. then repeat with further images and you will end up with images like this one or like one of mine :