Whether you're 18 or 81 there is no hard list of dos and don'ts for what you should wear. The one thing you should always do is wear whatever makes you feel good.
Turning 40 doesn't mean you're “too old” to follow the latest fashion trends-if you like a style, then rock it. It’s all about how you feel in the outfit more so than what other people think of your outfit choice; if you love it and you feel good then no one else's opinion will matter.
Remember when skinny jeans were the hottest trend? For a good while everyone thought they were meant for younger people that if a mom tried to wear them she was just “trying to be cool”
Now I see women (and men) in their late 50’s rockin’ the skinny jeans and nobody cares.
The same idea goes for any new trend, it's always “meant” for the young people and then eventually no one cares who wears it, but here's the thing no style is really meant for any age group, it's just clothing and no matter what your daughter's friends might think you look awesome in those cow print bell bottoms!
Wear what you want, whenever you want, and FORGET whatever negative opinions are made concerning your clothing. It’s your life so break out the happy pants and get to groovin’!