Just applying for another card hurts your credit. For example, when I applied for a credit increase my bank used the same kind of check that a new CC would have had and the credit rating increase from the increased CC limit was entirely offset by the hard inquiry on my credit report. It takes 2 years for a hard inquiry to go away <_>
Using >10% of available credit is also a detriment, >30% is a pretty moderate hit to it. When I dropped my CC usage to