Cryptic clothing requirements

I have a scientific mind. I glory in recognizing interesting ecological phenomenon. I revel in the physics observable in daily life. I unfailingly point out the difference between correlation and causation. I believe in randomization and embrace entropy in all experiences. But I am utterly ignorant about being fashionable. For me the most difficult part of preparing for a presentation, conference, or business meeting is packing clothing.

It is so much simpler to choose clothes for field work. It's all about the utility of the clothes not how the clothes represent you. Dressing to prevent sweating during high physical activity in freezing weather, no problem. Need to dress to prevent heat strain and protect against insect bites while collecting data in a swamp, I know how to dress for that success! But what the bloody hell does "business casual attire" mean? or "dressy casual"? There should be an illustrated guide book for graduate students clothing that I can take with me to the store to help me choose clothes. I can never tell if the outfit I'm trying on is trendy and cute or absolutely ghastly. I think most fashion trends must teeter on the edge of ghastly. What I need is a store without fashion trends. Just very basic shapes and colors that an apparel guide book could catalog and direct the dumbfounded grad student through. And oh, don't get me started on picking out a hair cut....