For me personally (even though I only have 1 video so far, haha) I write down all my ideas whenever they just pop into my head. My kind of video is probably really different from yours, but I think it still applies. If you write down a few ideas you have, more will flow easily because you won't be afraid of running out as soon as you finish your next one, since you'll have a buffer of some sort! I think that takes a lot of the stress to come up with an idea off.
So I guess if you're strapped on ideas, sit down, relax, and just write a few things that pop into your head, and work off that! Then the rest should come more easily : -]