Where Do I Get Reference Pictures?
The internet is your best tool for reference pictures because it is so easy to find them! When looking for reference pictures it is always good to choose a variety of references to get some different views of the costume. I like to have a mixture of: Screenshots of the media, fan art of the character, and photos of other cosplayers.
To get screenshots of the media you can:
How many times do you expect to wear a costume before "retiring" it