Here is a quick overview of the process
1. I took a picture of myself and overlayed a picture of Lego Batman on top in Photoshop. Lego Batman doesn't scale to a normal person, so I had to play with the proportions. I scaled the image to exact inches, I did this so I could use the measurements when making my cuts.
2. I started cutting up carboard and duct taping everything together. The body, legs, and hands were pretty simple. Gorilla Tape works really well, I took my time with the tape to minimize wrinkles to keep it looking as smooth as possible.
3. To create the mask I printed out a scaled version of the mask using http://www.blockposters.com/. I then used that as a reference for cutting my cardboard. I started with the base, the ears, then worked my way up. This was challenging because it has curves but the cardboard doesn't curve easily. There is alot of trial and error involved in this step.
4. I started spray painting all the parts. For the body I printed out a scaled out template of the body art. For the bat symbol I cut it out then spray painted it, using the cutout as a stencil. I then used the other parts as a stencil to trace the pattern onto the body with pencil. I handpainted the utility belt and muscles with acrylic paint.
5. The cape is made of felt, I just cut to fit, then cut the curves out of the bottom.
6. The last part was putting it on, I made duct tape straps and connected them to the legs and held them up like suspenders. The helmet just sat on the body.