Okay to start off you are going to need some software first, what you will need is a recording program like Fraps for example, and VirtualDub. that's about all you will really need.
Now assuming you already know how to record the video and you have the recording you just need to start making the Gif. here is how you turn your videos into gif animations.
First off you want to open the video file on virtual dub and play through the video to make sure it looks right for what you need. Now we have to set the recording time frame. we do this by going to the starting point in the Gif and press "Home" and the ending point of the desired Gif and pressing "End"
If everything looks the way you want then it's time to start by cropping the area you want, you do this by going to Video > Filters.
Now we are just going to add a filter that won't do anything simply to be able to crop the video, so click Add and then Brightness/Contrast and then click OK without tampering with the settings.
Now we can finally crop by clicking the "Cropping" Icon.
A new window should pop up, now you can start cropping the video by pulling the corners and sides together to box in the desired area.
Now some advice I would give would be to use the bar at the bottom to run through the video a few times, you want to have enough space for the skill effects. Don't worry too much about particles but make sure they have enough space to at least be seen at their fading point. And when you are finished click OK on both this window and the filters window.
Now you are ready to export! go to file > Export > Animated gif and add the desired name for the file by clicking the "..." icon, and make sure "Infinite loop" is checked! Now to press OK and let the video export!
Note: It may seem slow when played on the windows picture and fax viewer but will be much faster on an image hosting program like photobucket.
Good luck all!