I will show you how to make bo shuriken that works great.
Step 1: Preparing Materials
You need to get some long, straight and hard steel wire or something similar. If it is rusty you need to clean it up.
Step 2: Making the Tip
You need to make a sharp tip on one side of wire. You can do it in few different ways. I use the tool on the image down. There is also very slow and not very good way.. to sharp it up with rasp. But you wont get smooth surface as with mechanical table grinder.
Step 3: Hardening the Tips
If you want you can harden the tips. You need to warm them up until they turn red and very hot. Then you need to cool it down really fast. You can use the items on images down.
Step 4: Finishing
When you are done the tips should be black or gray. After that put some wicked paint job and you are done. All you now need is place to practice and some good will. Good luck