Things that make me think spud:
-Tshirt under a tabard, instead of a tunic.
-Sports bras instead of tunics.
-Soccer shorts or cargo pants (with those obvious pockets) instead of garb pants.
-Obviously modern shoes (nikes, white or colorful sneakers).
-White socks that aren't covered by pants or boots.
-Sunglasses and obviously modern bandanas (that look like they're out of Huck Finn).
What I like to see from a newbie:
-Attempt at a t-tunic (can be unhemmed, or even just a sheet with a hole in it, held together by a belt). There can be a tshirt hiding under it, but there's obviously an attempt at a tunic over top of the tshirt.
-Sweat pants, pajama pants, or some other attempt at pants that are non-descript.
-Shoes that aren't nikes or bright colors. Preferably black or brown sneakers, or sandals.
The minimum I expect of a veteran:
-No visible tshirts, underarmor, or sports bras.
-A tunic that is hemmed, or a really nice medieval shirt.
-Pants that don't stand out, preferably better than scrubs or sweat pants.
-Shoes that don't stand out from 10' as being modern. Either non-descript earth tones or something period (whether medieval or fantasy).
(Edit: notice how little I expect of a veteran... I am not a garb Nazi!