>>7284528Really easy. Small stuff is easier, like the buckle, the leg pieces take more work. I just press the piece into silly putty, kind of form it around it, pull it out, and fill it with glue. For the thigh armor I kind of stretched it out flat to make the mold and then after I cast it I took it out and heated the underside with a lighter and bent it while it cools. If you're careful you can reuse the mold, both thigh pieces are cast from the same molding. I'm way too reserved to paint up actual pieces or use them on a dumb custom like this, so it's a great, cheap way to get more.
If it's a bigger piece, you should go back and forth across the narrowest part to fill it with glue. Kind of like a printer. That way hottest glue is sticking to the next hottest part and it forms together and you kind of get a gradient of cooling without any ridges. You can see on my lizard's shield what happens if you go too big or parts dry too fast. I need a full-size, high temperature gun for something like that.
And hot glue is pretty sturdy, it's basically hard rubber and takes spray primer really nicely.
Don't try to use modeling clay, the heat from the glue liquefies it and you have to dig it out of the details, silly putty is the way to go.