The best and most honorable and professional way is to show 1 year's worth of positive returns....verified thru an independent certified public accountant. You then show this to friends and family and say you are looking for seed money to start a trading business....and see who, if anyone, bites.
This is how I got started. My first year's returns(2007) were positive, trading FX and energy futures on an intra day basis. I got a CPA to verify my returns at the end of the year. Then showed my mother's childhood male friend(who is now a very successful cancer surgeon in the Wash DC area and is like an uncle to me). We talked about it for a few weeks over the phone, and at a birthday party he had at his house one weekend for one of his daughters(has has 9 children...half of them adopted), at the end of the party he handed me a check for $250k.......with many conditions!
Nobody is going to offer you start up capital if you can't show(with proof)that you're already making money trading with proper risk management parameters. To think otherwise is to live in a fantasy world.