A little over 2 years ago I got a Sams Club card with a 300 CL. It took awhile but now its up to 2400 which I am using to play the FICO score game. I think it took a year for my first CL but then there came much shorter.
I dont know if there are any use patterns that will improve or lower your chances of a CL. My instinct says that if you max the card out but you pay it all when its due is not a good idea. I know that your max iut balance could get reported if the timing is right and is they or someone else pulled you score at the moment, it would be lower then it should be. Timing, they say, is everything.