Leggings and tights are called "leggings" and "tights" because they are NOT PANTS! They are not a stand-alone article of clothing.
Don’t get me wrong; I rocked the leggings look all through my childhood. And now that my childhood is making a fashion comeback, I myself own a few pairs. However, there are strict rules governing their adult usage, and here are the acceptable cases:
Under age 10? Definitely. (But don’t be that weird kid that takes too long to make the switchover to jeans after that. That was totally me, and looking at photos, it wasn’t pretty.)
I'm the shrimpy one in the middle channeling a green Where's Waldo
Under a dress? Perfectly acceptable.
With boots, a belt and a baggy sweater? Sure.
Although the lady on the far right has taken the robe look dangerously far into jedi knight territory
Under shorts? Cute.
This look always reminds me of Mickey Mouse
The last appropriate usage is any sort of theatrical use. Dance routines get a pass, as do any Halloween tributes to Freddie Mercury, David Bowie or the like.
When I was in third grade I used to laminate all of my notebooks
in holographic contact paper that looked exactly like these leggings.
Unfortunately, it seems that lately the boots, the dress hemlines and the sweaters have all been shrinking, leaving me faced with faced with more detailed information about strangers’ anatomy then I would ever want. If you wear your leggings like Snooki, then you're as big of a flop as she would have been less than a second after this photo was taken.
In summary, the key concept to take away from this is UNDER (or over, but only as in I am so over camel toe). Feel free to rock those leggings, tights or jeggings, but remember: if they're not beneath something, the style's beneath you.
And now I'm sure you're all underwhelmed with my layering punnery. Over and out.