Do keep in mind that while it's important to work out any kinks before taking it onstage, the longer you wear a costume, the more chance there is that it might get messed up. Wigs, especially, will start to look mussed after hours of wear. If it's a complex costume and/or you want to make sure you look perfect onstage, it might be a good idea to test out the costume at home and then put it on only when necessary for the competition.
I agree with CapsuleCorp in that many really big and/or bulky costumes are not really very well suited for wearing all day and are best for stage. I'd say the same goes for really long wigs.
Of course at the end of the day it's all up to personal preference!
COSTUME-CON 32 - 2014
the den of sarcasm - my website
Magpie Creations - jewellery and wa-loli accessories
The International Costuming Convention is coming to Toronto Canada!
4 Days! 4 Masquerades! Dealers, Tours, Parties, Costuming Panels and Classes, Cosplay, Props, Doll Show & Competitions, Steampunk, Sci-fi, Fantasy, and so much more!