Tip: Shellac is a great way to seal your armor to protect the paint. It dries fast and is very durable. I also add bits of velvet fabric into spots where the armor rubs together to cut down on paint abrasion.
Tip: Using LEDS in your costumes is easier than you think! A good way to diffuse the harsh bulb is to set the LED behind tissue paper or a sanded piece of plastic.
Tip: Reinforcing your strapping with chicago screws or other mechanical attachments will help insure you won't have any breakage while on the con floor!
Tip: Anywhere is a nice place for a quick photoshoot, but pieces from your cosplay migth fall, always bring some basic tools like pliers, wire and duct tape on hand.
Tip: If you wear a heavy costume don't forget to sit down and recover your energy. Also, practice the poses of your character at home so you can look more natural on camera later.