The first real prop I ever made for a cosplay was for my Yukari Takeba (Persona 3) cosplay: a small pistol-like weapon called an Evoker (in the game, the characters attack by summoning spirits called Personas–in P3, characters summon personas by pointing an Evoker at their own heads and pulling the trigger). I followed this tutorial by Gen from Team Blasé, and it turned out pretty nicely, considering I had no experience at all making any kind of prop.
But tutorials are good for more than telling you how to make specific things. Good tutorials teach you techniques that you can apply to other projects.
Making the Exalted armor set from Guild Wars 2 was my second GW2 cosplay; unlike the first one, I decided to choose a specific class to portray and make a corresponding weapon set (photoshoots are so much more fun with props!). I chose to portray a sword/pistol wielding Mesmer in part because I had an idea of how to make a small gun based on my experience making the Evoker. I made the handle and base of the gun the same way, by cutting out differently-shaped layers of craft foam and gluing them together to make a 3D object.
Here are some progress photos from the Ebon Vanguard Pistol:
After creating the base out of craft foam, paper mache, and spackle, just like I had done with the Evoker, all that was left to do was create the details using other techniques I had learned along the way. I made the “wing,” the handle guard, and many of the details out of craft foam, following this tutorial for craft foam armor. The barrel is a thick dowel cut to size and attached with gorilla glue. Here’s the finished prop:
This is why I love tutorials and have a huge folder full of bookmarked online tutorials. Even if they’re for something very specific I may not be interested in making, chances are they’ll teach me a technique that will be useful for my cosplay arsenal.