Help?

Hey y'all. So, my boyfriend and I have started talking about marriage. No, he hasn't popped the question yet but he did say that when he does (he's waiting to have the money for a ring and for us both to graduate) he isn't gonna wait long to tie the knot. So, here's my current question, what are some good themes and how to pull them off? I'm likely gonna go ahead and start planning everything and getting the idea of what I want in my head so when we're finally ready we can just dive in head first.