My personal goal was to make it look the stormtrooper was in battle on ground rather than desert i chose oil and smoke appearence as weathering by using paint spray and spunge.
Before i did all of that i open my window in my room and i started heating up the blastmark with a torch lighter. It made the plastic soft in the area i was heating. (PS make sure the point is above the lighter to get a round mark. If you want a strafeshot tilt the armor the way you want it to be stafeing.
Once you heat up the armor it will become soft in that area. Press with your thumb (watch heat) or other item to make the dent in the armor. In some areas tear of the plastic from behind and you will get a hole going trought all depending on how seriouse damage you want. Other areas like the back i heated it ut from the outside first then forced it inward. I then toor apart the plastic from the inside and then heated it up again to force the plastic back outwards to make it look like it was a direct hit and it was a blowback from the iterior comonents of the armor. I use radio and old computer boards and glued them on the inside of the armor. So when people look at the damage they dont just se a hole.. They accually se something making them ask them self allot more questions that just a hole.
Let me know your thoughs. PS. I plan to buy a small smoke machine to make the back pack shoot some smoke out to make it look like its just recently hit. Whats your thoughts on this.