Surprisingly, the best source of financing can be from out of your own pocket.
The term "self-financing" includes using your own money to invest directly in the company and using your personal assets as collateral for outside funding. When you self-finance your business, it gives you complete control of your company and the independence to do what you want.
If you do turn to banks for funding in the future, it will speak volumes that you invested a significant amount of your own money into the company. After all, if you don't have enough conviction in your business to jeopardize your own money, why would anyone else?