1 - Select a card with no annual fee.
Having 4 credit cards is optimal, but not if each of them is costing you more every year than you're benefiting.
2 - Pre-paid debit cards only help if they report to the bureaus
Make sure you do some additional research into the card, even if you have to call them. Make sure they report your account to the bureaus (which increases your "Types of credit" & "credit limit", along with your good "payment history"!
3 - Do not rack up the inquiries
Applying for several cards, when you only need one will put several "hard" inquiries on your report - decreasing your score. Find the right card, then apply for it, and wait for an answer.
4 - Give yourself the best chance for approval
Applying for a credit card that isn't for "bad credit" individuals, and checks deep into your past will do you no good if you know you'll be denied. Go for a card that is designed to help you rebuild.