I open the video file in After Effects first, then force a little extra motion blur to the replay to make it look more like the replays in the trailers. With some gifs like the Ferrari 458 below, I added some extra effects such as messing with the colours and adding a blur at the start, and the nascar video I added a camera wobble so it looks a little more realistic. Once the video is rendered, I just open in Photoshop and save it as a gif.
