Well, the advantage that you have over your grown up competitors is that you do not have 1. a bureaucracy to support and 2. a minimum profit margin to report to investors.

Thus, you can more mobily snatch up the jobs that your competitors will be debating about for weeks or months while you can offer to start in days or weeks. Secondly, if this looks like a possible long term or long series of jobs, offer to do the first one for just cost to prove yourself.

Additionally, if you have a niche that you're specialized in, that should give you an advantage that the big boys who are more general may not have.

Now if you are looking how to get in and have that first meeting, you're going to face the same tricks as the big competitors. Use what ever method you have to get your foot in the door, there is no silver bullet.