
On topic again- Most all the bases have been covered here. Enjoy what you make, because in the end you're making AMVs for yourself first and for anyone else second. You're the one that has to sit through the process of making your idea come to life, and it'll be quite hard to do that if you don't enjoy what it is you're doing.
And also, don't underestimate the usefulness of watching other people's videos and learning techniques from them. The better you can take apart other people's videos technically from watching them, the better you'll be able to put together your own (well, in my experience this is true anyway).
Don't lose your own style in watching other creator's videos though.