For the most of the days I choose what I truly feel good in, which is usually denim. This way I almost always use the easy way in order to receive that comfortable but stylish look. Here are some ideas that helps me:
1. There is no rule to obey, the only rule is to wear what to want, not what others expect you to wear.
2. Choose to wear what fits you perfectly, the true size. If not, adjust and tailor it before wearing it.
3. Use more basic pices, like denim, white tee etc
4. Wear what you want, a dress, a suit, any elegant piece you love, but add a pair of white sneakers or platforms.