My advice:
1) Get only 1 credit card. No need for more. Most store cards aren't worth it. Get a chase visa or similar with a good point system for rewards.
2) pay off CC at the end of every month if possible.
3) Never miss any payments. If you're short one month, get someone to help you out and pay them back.
Some may argue that you build credit faster with a balance - not a high balance - but say you have $500 on your CC. If you pay it off slowly - like 1/2 at a time, it supposedly shows that you are responsible and can pay off loans if you don't have cash at that time. At one point when I was unemployed and had almost $2,000 on my card and thought i was going to have a heart attack

I just paid as much as I could , and then paid it off over time once I got another job.
I don't see how a cell phone bill will improve your credit - it won't. Run your credit through one of the 3 major corporations - I just checked mine yesterday as I do every year, and it shows every credit card and loan I've ever had. From my Express cc i got when i was 18, to the car loan I paid off, and my school loans. They don't show your cell phone history. They run your credit to see if you're likely to screw them over on payments within the next 2 years of your contract - that's all.
I've only been late on 1 payment ever - and it's on there. My car loan for $18k paid off in 5 years, and my CC have $0 balance monthly - I charge items, then pay them off in cash a couple days later via Chase's website.
My credit score is almost 800 and I'm only 25. It hasn't really gone up much in the past year either. I'm not THAT old. Just don't get in credit card debt like a lot of young kids do - I have my friends that are 25-30 years old and have $15k-$30k in cc debt (and a couple of them are buying the new iphone...why buy a $500 upgraded iPhone when you have $30,000 on your credit card?) MORONS
Credit builds with time. Just get a credit card and use it to buy stuff, then pay it off
