the way it works is a company looks at your credit for the past two years...they cant see what happened before that unless the company put it in a comment section (very rare).
i would keep the cards you have PAID ON TIME FOR THE PAST 2 YEARS. two or three should be enough. if you arent wanting to have them because of temptation then only get ones that are or gas only or like a kohls card only for their store. and then make sure you pay the total amount each bill.
another thing that affects your score is the debt to income ratio or amount able to borrow/use. so the cards that you do keep call them up and lower the amount you can borrow/spend on the card. you can always call a card up and have them raise your limit again and if it was already that high before the chances of them raising it back up right then and there is pretty good.
another idea is to keep that card in the freezer in a block of ice. this makes you have to think long and hard about wether you should make that purchase while it thaws.
you want to have some sort of bill every month that will turn in your bill status to the burough each month. your regular power and water won't. your mortgage and car payments will and student loans or even the hospital. but if you only have one of these i'd think about getting that gas card and using it for gas only. discover gives 5% back i believe on gas purchases so that helps too. i know others that have all of their normal bills like power, water , internet and phone be billed to their credit card so that they get points or money back and then they use that money they earned to buy christmas presents that year. you were going to pay those bills anyway so this is a nice way to do it where you won't even have to hold the card you can keep it in the freezer where it's safe from your hands yet still be making you money and saving you money at the same time.
if you do transfer your balances to a 0% card make sure you watch to see what they will charge you to do that. some charge 3% of the ballance but otherscharge more like 5%. at this ppoint depending on the amount you owe and how many months you will be at the 0% you may not be saving anything. and try to get the ones that go for 18 months...i wouldnt transfer to anything that gave me less than 12 months.
good luck on your journey to financial freedom:)
if anyone reading this is interested in going to a class that teaches financial freedom i know that first baptist church of norfolk has them on occasion. check out their website at firstnorfolk.org or call them to see when a new one will start. they are on their second week of one right now that meets wednesday nights at 6pm if anyone is interested.