As someone who had the privilege of judging last season's hopefuls in the Chicago Castings, I think I can give you some first hand experience from a "judge's" point of view (as well as from an Instructor of fashion design!).
1) First impressions are VERY IMPORTANT, you need to LOOK THE PART. Dress stylish, "cool/hip" , coordinated yet still professional. Certainly not a suit, but let's just say: Don't look like a fool. Pretend you are meeting with the head buyer of Barney's NY or Saks Fifth Avenue and you want to sell your line to them.
2) Don't lie on the application! You REALLY do need to know how to sew, do patterns, drape, and sketch. If you lie and get in because of your "personality", you will crash and burn when it comes to those challenges. You really do have to make a gown in 8 hours. There are no "petite mains" sitting in some workroom waiting to sew your garments! (If you lack in the any of these departments, you may want to begin taking some lessons ASAP! Or at least get to know what glues work best on fabric!)
3) Bring a PROFESSIONAL model with you, if you are able to. Not your 15 year old cousin from Tarzana who took modeling lessons at Barbizon. Not a Drag Queen (one designer hopeful did this in Chicago!) It helps the judges to see one of the garments on someone. It was my "secret weapon"!
4) Keep the cheerleader and dance-number costumes you "designed" for your daughter or sister at home! As well as those patchety-patchwork vest and bedazzled sweatshirts . Please. Have a well edited, well made three garments/outfits.
5) Make sure the pieces you bring have a common theme and are not "all over the place": Example: A "Christmas Sweater" here and then a gown there...
6) Also, remember that , even though the show is about TALENT, it is still a REALITY TV SHOW!! Very important to have some sort of "personality". If you are bland, boring, etc. It will not make for "good TV". If you want to go the Santino or Jeffrey route and go there wanting to "be a mean theatening 'character' ", go ahead. I don't like it, but I realize it is, in the end, A TV SHOW, and they need TV CHARACTERS.
7) Try to be humble and take the advice well from the judges. They are experts. Don't bitch back. It doesn't gain you any points. You will just look silly, like those kids on "American Idol".
8) Lastly: DO NOT bring a "Skirt made out of ties" or a "Dress made out of ties", or ANYTHING made out of ties. Tim Gunn (and myself) wanted to reach for the nearset barf bag any time someone walked in with any of those. It's not creative.
As always, Love to you and BPR!!!!!