The Loan & Credit Grandmaster

This video explains where and how to get money in your bank in under 20 minutes for an emergency, or "quick need" situation. You need a bank account (not negative balance) and a 550 FICO score.
Helpful Credit Tip: If you have a credit card with a $3,000 credit limit, try to keep your balance between $270 & $870.

Do this among all your credit cards, and you'll see a higher score on the next cycle that bureaus follow on updating scores.​
Of course, other more obvious ways are paying on time, paying more than your minimum payment, not closing any accounts,
and if you are an authorized user on someone else's account, and they are doing poorly in these areas, asked to be removed.
Keeping your balance at zero is not ideal, either, as credit card companies issue you cards so you use them, so they make money. If you go too long without using a card, they may cut the limit, or close it entirely, hurting your score, by lowering your overall credit limit among all your cards.
Watch YouTube for more "Loan & Credit Grandmaster(TM)" videos, on credit, business, loans, and secret tips!