It's come to my attention that many project creators probably don't quite understand the notion of project marketing. Heck, in all my years of working with indie developers I've found that the greatest weakness of developers, in general, is marketing. Which isn't too surprising given that it's actually a really difficult proposition.
So, with that in mind, here are some tips to help you promote your project in order to get some funds:
1. Friends and family
Oh yeah, these guys are gonna be huge in generating contributions. It's important that you let your friends and family know what your working on, why you need help, and how they can help. Being close to you they have a vested interest in helping you along, after all that's why they are considered your friend, or even better, family.
Of course, most project creators will, instinctively, blast Facebook and Twitter, both of which are fantastic means to communicate a brief idea of what you are working on/need help with. However, when dealing with your close friends and family, go the extra mile. At the very least send an email to them specifically letting them know that you'd appreciate anything they can offer, even if it's only a couple dollars. Putting something up on your Facebook wall these days is pretty impersonal, you've got to make the extra effort to ask.
If you're developing a game, you should have fans or at least people curious about your project, unless you're intentionally keeping it quite, in which case, why are you creating a project at all?
Many developers acquire fans through their dev blog, of which many use services such as ModDB and IndieDB. These are great resources to help build your fanbase.
Anyway, where I'm getting to with all this is that fans are the next best source of contributions, especially the ones who are fans prior to the games actual release. Offering up contributions that include them in some way is a huge motivational factor in getting them to donate as they'll feel like they actually helped development (which they did).
Beyond that, as fans of the concept, idea, etc. they naturally want to see the game become the best it possible can be. Let them know that by contributing they are actively funding a better game.
3. The community at large
In no way am I encouraging you to spam. Don't do it. It will make you look bad, it will make us look bad and overwhelmingly people just won't respond positively if you try and spam your project.
That said, utilizing the community at large isn't completely against the rules. Let's face it, as gamers we like talking about games which means your probably apart of some sort of gaming community out there be it a forum, reddit, digg, etc. Use these places to your advantage. Put a link in your signature and/or request an admin to allow you to put up a post about your game.
Bottom line, the gaming community is VERY generous. Over the past few years we've seen how generous they can be in supporting endeavors of other gamers. Use your communities in this manner and don't be afraid to put yourself out there to communities you are a part of.
4. Appeal to press
This is something I've been telling indie developers since the first day I founded DIYGamer.com. Talk to the press, get them interested in your game, offer up previews, reviews, interviews, etc. Once you've got a project running, go the extra distance to get anybody and everybody to talk about your game. From there, get them to include a ink to your project fund somewhere in the article.
These guys are there to promote you, don't just sit back and wait for them to come calling. Believe me, as a member of the indie press, there are about a thousand other games I could be looking at on any given day.
5. Think outside the box
Don't rely on this list as your only means of getting the word out. There is always an opportunity to talk up your game, your project, your need of help. Go to conferences, meet up with local developers in your area.
Keep in mind that funding a project is a job. This is not something you can create and then just let loose and expect to be successful. It takes work, it takes commitment, most of all it takes the desire for you to actually want this kind of funding.
I hope this has helped you in some way. If you think of anything else that you've found successful, feel free to chime in on the comments.