One important aspect is to have a good idea of what the judging committee is looking for. Some hackathons are going to be decided by your polish and presentatio

One important aspect is to have a good idea of what the judging committee is looking for. Some hackathons are going to be decided by your polish and presentation. Others are going to be biased towards more technically impressive projects, perhaps with less polish. I've certainly seen both kinds. Also, I've definitely seen some projects do less well seemingly because the judges didn't realize how impressive they actually were. If you're doing something that's very advanced but correspondingly obscure, you have to be careful to convey that in your presentation! And, of course, as with any such endeavor, don't be disheartened if you don't win even with a great project. Having something that works at all is great in and of itself, and the judges have to choose from a whole bunch of projects in a very short time, which necessarily means they can't consider any of them too deeply.