I like my animated gifs to be without any jump when the animation starts all over again. This is especially difficult to achieve when you’re using a short part of an existing movie.
I often use the trick of reversing the clip in iMovie.
First I located the movie on YouTube and watched it to see what scene I would like to use for my animated gif. I choose the scene where the scientists see their moon capsule for the first time. Then I started the screen capturing tool of QuickTime by right clicking the icon in the bar and picking “screen capture” (in Dutch it reads “Nieuwe schermopname”).
After recording a little bit more than what I needed for my clip, I saved the movie clip.
Next I opened iMovie and imported the movie I just saved. I cut away the parts I didn’t need and then copy/pasted the clip in iMovie.
To reverse the copied clip, I highlighted it and clicked the turtle symbol in the tool bar in the right upper corner. There I clicked “reverse” (in Dutch “keer om”).
I saved the result to a file on my computer and went on to Lunapic, an awesome free online tool to manipulate images, video and gifs.
In Lunapic I choose “video to gif” and uploaded my clip. I added a caption using the option “add a caption” and saved the result to my computer.