First, at the risk of death I wanna nail my colors to the mast and say I've never got the frequent comparison of many fans to military uniforms or sports jerseys, so I dont' personally get why people wear them, but whatever people wana do is fine my me.
Where I live there really aren't any conventions (that I'm aware of) and thus I've never seen anyone in one in person.
I have noticed however that in documentaries like the trekkers ones there is a difference in how...realistic the uniforms worn by fans look.
By that I mean, how similar to the ones the actors wear they are
In the trekkers Documanary I saw many that were just badly taylord, didn't seem to fit right or had poor detail like ridicilously oversized com badges.
Then I saw one guy with an Admirals uniform that looked identiacal to the one Ross wore in DS9 in every way and it looked like he could have just walked off stage.
For those who wear them, is it a tayloring thing? hard to find the right size? and what gives with the poor details like oversized com badges, dont' you at least want it to look like the ones on tv?