Dunno if this is the right forum. Wanted to share this video with you where I made a gut knife and Karambit both crimson web and tiger tooth. Maybe you are interested youtu.be/IB4ZAcsTM3o for all the others. Yes yes let the hate flow :P
I understand your point but 3D printing it is the closest to DIY in my opinion.. They are rather cheap to buy. Yes you could made them out of foam. But also you have to invest a shit load of time. How would you make them more DIY?