The key to good videos is also the key to good photographs: keep your camera with you all the time, keep it charged up and loaded up, and keep your eyes open. If you wait for something interesting to happen, then need to pull out your camera (or, god forbid, you need to go GET your camera) it's probably too late. Photojournalists know this. They wander around and look at the world through their viewfinder. Now if you're a normal person, this is no way to experience your life: to shoot something is fundamentally to miss it, to miss experiencing it. But there are times when the risk is probably worth it, when you can do something with your camera out, at the ready, shooting here and there. Do this enough -- whether it's on a vacation or just at home -- and you'll undoubtedly end up with lots of useless video AND one or two absolute gems.
I have a video on YouTube that i did not stage, that I "just happened to shoot" and which has now been seen about 250,000 times. It was one of those freakish things you just happen to see when you just happen to have your camcorder out. I had to make a snap decision as it unfolded: try to 'cover' it the way i might for editing, or just SHOOT it as one continuous shot and deal with the consequences. I had to think about this while I was actually shooting. It's not a sketch - like those i evangelize. It's not even that good. But the event is so unusual it doesn't really matter. So there you have it. Rules. Broken rules.
As geeky as it feels, keep your camera onhand, and shoot a lot (and also know when NOT to pull it out). Shooting alot does not mean shooting everything. Pick your battles, your moments. Then see what you can create. It's treasure hunting. Lots of dead ends and the occasional gold coin, and if you're lucky, maybe once, maybe more: the motherload.