Whatever you want to make (comics, books, animation, etc) is what you should be putting your time, effort, and money into. So if you're trying to get someone to sponsor you to make your comic, a trailer is not really the best idea to be putting the majority of your effort into. If you're trying to get someone to greenlight an animated series, then maybe? I'm not sure.
If your goal is to be paid to make your own comic, it makes sense to submit something to Hiveworks, Tapas, get an agent, etc.
There are no short cuts but there are plenty of options!
As for me personally, I'm really happy just working on my comic. I don't want the pressure of being beholden to anyone else right now. I'd like to make money off my comic(s), and possibly for a future project I'll pursue that harder, but right now I'm glad I can do my own thing, and have room to grow and explore.