You talk about not finding a job (as in being employed) but also a firm? are yo trying to become some sort of sub-contractor?
If someone hires you to actually design and be responsible for the design (not just being a project hourly hire or so), they typically want you to have liability insurance etc. that is a bit expensive if you just have a gig here and there. I once worked as a sort of sub to a consulting firm. but instead of hiring my firm (I have an LLC in addition to my regular employment) they decided to hire me as an hourly employee on an as-needed based. i got paid quite a good hourly rate, but had no benefits and only hot hours when they needed me. It was goon in that i didn't need to have legal responsibilities and needed insurance etc. they kind of had a longer term plan to hire me fully, but at the time I wasn't ready to leave my old (and still current) employment. (and yes, I had informed my current employer about my "2nd job" and also clarified with the attorney's office of my employer to be on the safe side). it wasn't bad to have soem extra $, but it also was that all of a sudden i had to spend some nights working to finish a project, and then didn't have work from them for a few week. Wasn't a problem since i had a full-time job, but not ideal if that is your only job.
you may want to see if someone hires you like they hired me on an hourly basis with no commitment. this doesn't' guarantee you a lot of work, but gets your foot in the door, and experience. If it works out, you may move up.