I have this problem too, particularly as the type of specs I like (thick plastic frames) don't have separate nose pads, and I have a very very low nose bridge (typical of many people of East Asian descent). I just live with it to be honest but would love to hear any suggestions.
I have heard that if you buy specs in Japan and other Asian countries, they often take the low nose bridge into account when designing specs. (I believe you have to get the ones made for the Asian market though, not Japanese brand specs made for the American/European market). I also know that some shops that cater to an Asian clientele can modify frames to have nose pads, but I think this may change the overall look of the frames as well.