Leggings are "IN" and are a great (and comfy) alternative for your bottom half. That being said, there are some very important guidelines that responsible adult women should follow when hiking up any form fitting elastic britches.
First and formost, leggings are NOT pants. Anyone who thinks they are and wears them as such usually comes off looking like they just did some yoga or just came off a street corner. (If you feel as strongly about this statement as I and many others, feel free to join the 'Leggings are not paints' facebook page .) Anyways, getting back to the point, leggings as pants = way overexposure. Instead, you should be thinking about Leggings as an accessory. Always be wearing a tunic top, skirt or mini dress over leggings that cover your front and your butt. The exception to this is Jeggings (jean leggings), you still must cover your front, but you can let 25% of a cute bum show.
ok, thats the biggy. Now how to make leggings work for YOU:
Across the board I recommend solid neutrals like black, gray and brown. please for the love of god, dont even attempt a pattern or bright color or worse, white.. you are an adult, don't dress like a 12 yr. old even if they come in your size.
Second recommendation for legging rookies is to pair a loose top or dress with the leggings. Loose on top will balance with the fitted bottom. It will also help hide a roll or two that the elastic wast may or may not have created. The trick with the elastic waste band is to always buy a size bigger then you normally are...creates less muffin top.
It all comes down to your comfort level, but dont be scared! Don't tell me your too old and don't tell me your too fat...your NOT. Leggings done right are a hot and chic' for anyone.