1. Do not wear a light wash in jeans, they are barely attractive on the young and they are especially not attractive on an older man.
2. As men age they lose their behinds. Having jeans with extra fabric hanging back there, only makes matters worse. If your jeans hug what you have it's much more attractive than all that baggy denim.
3. Your denims can be altered to fit, just like anything else. Big sloppy, stretched out jeans are not attractive, have your jeans altered to fit you.
4. Stick to a straighter leg, it much more flattering than a wider leg.
Here are some examples of good fitting jeans. They have a comfortable feel but fit and give the guy some shape. Older men you could wear them just a little tighter for a more dressed look.