Grants can be a worthwhile thing to help get funding to do new work and also can help expand the network of people who care about the music you are making. New Music USA is set up almost like a social network of composers and performers and really hits a sweet spot in terms of funding actual work, as opposed to funding venues or the other not-the-music aspects that surround musicking.
How do you get a grant from New Music USA to help fund your performance of new work for double bass? Here are some tips for making your work samples the best they can be. And some general thoughts on getting the application right.
Of particular note: keep your production values as high as you can on video and audio. MIDI is considered a low production value thing.
There are also a couple good bits of information in the comments of their post so be sure to scroll down for those as well.