I cringe at the part in the movie Legally Blond where Elle trots up to the party and comes in dressed like a Playboy bunny when really it's just a regular party. People snicker, point, gossip, and Vivian even spews her champagne. It was nothing short of disaster. Elle's skimpy bunny outfit was most definitely not the right clothing style for that particular occasion. Hopefully no one in the real world makes fashion faux pas on that large of a scale, but sometimes deciphering what is appropriate or expected is stressful and mind boggling. What to wear?!
There are some days when I stand in front of my closet and just stare at what I have. Some days nothing looks good. Some days I just don't like what I have, so I stand there in my pajamas while the clock ticks away as I try and figure out what to slip on. It's the worst when I'm going out somewhere besides the store or the office. Some occasions require a special kind of dress, whether it's a date, a concert, an interview, or a party.
The first rule I have when I have a clothing mental block is to dress on the dressier side if I'm not sure which way to swing. I'd always rather be slightly overdressed than underdressed and, frankly, I usually dress up more all the time. I'm accustomed to being the most dressed-up person in the majority of situations. It's always better to be wearing a skirt when most are wearing slacks and sport jackets than to be sporting your Saturday jeans.
If you're hanging out with friends, it shouldn't be too difficult to figure out the standard for the event because, well, they're your friends so you should be able to ask or just figure it out. For other events however like work parties, the symphony, or a school concert, the guesswork can be a bit sketchy. For a work party, you should be able to judge the dress from the atmosphere in the office, the venue of the event, the type of company, or if you're lucky, a specification on the invitation.
For events like the symphony or a play, the dress code has declined a bit in recent years. I still like to dress up to attend a Broadway show or go someplace where the performance is professional and I usually don't look out of place. However, more casual garb is becoming more and more acceptable. I still stand by the rule though that it's always better to be overdressed than underdressed.
Choosing the right style for the right occasion can be quite the ordeal. It can be overwhelming and even discouraging at times. I suggest you adopt my rule as your own: always dress up slightly more. That way you've created a safety net for yourself. If you can't feel it out well enough to make an accurate call, dress it up! Cheers to no more standing-in-front-of-the-closet stupors!