When creating an item, it's always good to have a good idea of where you are heading with the design.
For me, that usually means drawing up a couple of sketches and maybe even developing a few 3d models. If I had a 3d printer, I might consider just printing out these 3d models, but I don't. Besides, 3d printers only seem to print in ABS or other hard relatively brittle plastics, for LARP stuff we need soft foams. Perhaps I could print out a negative of the shape, the use that as a mould to cast foam....but as I said, I don't have a 3d printer, so that's not really an option for me.
Lots of images are good. The more images you develop, the better the idea you have of your end point.
So here's where I'm aiming with the hammer. I know that it won't end up like this, but it's got the right vibe for where I'm aiming.