If you’re trying to design for women, start by solving real problems. Too often, marketers and product designers think that they can slap some pink on a product and women will flock to it. Remember Dell’s “Della” line for women? Or Bic for Her, the totally unnecessary “pen for women” (and its ensuing Amazon reviews)? But let’s be honest: It’s not really a problem that the iPhone 5 doesn’t come in pink. It is a problem that …