With a mortgage, the key thing is to show banks you can make consistent payments, whether it be loans, credit cards, store-credit (littlewoods

) or even overdraft facilities, these will all be on your credit record. IE, I had to use littlewoods for one thing when I moved in and cleared it, 12months later my credit score still shows it's clear with them willing to lend upto £1500 in credit.
If you are after loans, banks get funny with people like me, as I always go out, get a credit card with x amount of months 0% rack it up and clear it quickly and onto the next card, the joys of trying to do up a house in stages! Loan companies absolutely hate this for one simple reason, they can tell you are able to clear the finances, but they don't see you as profitable, as all they want to do is make money, they are after people who will borrow for as long as possible and keep up with payments, in their eye's I won't make them money, which is dam right! Why would I take out 5k at 2k interest at 5 years when I could clear that in a year with a credit card.