1) Beg and borrow from the people who love and trust you in the hope that either (a) you'll repay them or (b) they'll forgive you - this is known as a friends and family round.

2) Find some rich people and convince them that they will make lots of money (in tax-efficient ways) if they lend it to you - this is known as an angel round.

3) (In some countries this is still possible) Go to the bank and explain to them the viability of your idea.