Once the yo-yo has come all the way around, you are now able to catch the loop again. This step is hard to capture, and is really, really ...
A suicide is a move that I view as the borderline between beginners and intermediate players. It is very versitile, rewarding, and most importantly, fun move that will possibly help you enjoy yo-yoing even more.
There are plenty of reasons that suicides are hard to learn, but here is some information and a tip that will make practicing them more enjoyable.
Keeping the string aligned is a maxim for most all yo-yo tricks that do not involve rejections, magic drops, or the like. (see the picture-in-picture about half-way through)
As a side note, your rhythm or pace will make a difference in the quality and ease of your suicides (especially the double suicide shown first!). Find the speed that is right for you.
Now get moving through the Instructable, watch the video a few times, and practice once you are finished.