I have seen a lot of people make really cool looking, ergonomic "Rambone" slingshots on Youtube and I wanted to try to make one myself. Since this am only my first try, it didn't turn out exactly the way that I wanted it to but try to bear with me and I hope this helps you.
Step 1: Materials
For this project you will only need a few materials:
• some 3/4 inch plywood
• wood glue
• large rubber bands (for the sling)
• small rubber bands
• some twine or other strong string
Some tools that you will need:
• jigsaw/bandsaw/scroll saw
• wood rasps (half round, straight, and rat tail)
• sanding sponges/paper
Step 2: Drawing
The first step of making your slingshot is to draw it out on a single sheet of plywood. You can draw it freehand like I did or download a stencil online (there's lots of them). It took me a couple of tries but I eventually worked out something that I liked.
Step 3: Cutting
The next step is obviously to cut it out. For this I used a jigsaw simply because I don't have anything else at hand right now but lots of saws will work for this. Make sure to cut right outside the line and pre-drill holes in the sharp corners.
Step 4: Tracing
After you have fully cut it out, you can put the blank onto some more plywood and trace out the design again and repeat the last step. After you cut them out, make sure that they line up properly. This isn't absolutely necessary at this time but it will save you some work later on.
Step 5: Glueing + Clamping
Now is the fun part. Apply a generous amount of wood glue to one side of a piece and push them together. Make sure that they are lined up as best you can get them. Clamp the pieces together and let it sit overnight. Don't clamp them too hard or you can actually squeeze all the glue out and they aren't as strong.
Step 6: Rasping
This step is the longest of the bunch. After all the pieces dry completely you can start rasping. I decided to attach another small piece. Right above where your index finger sits. I used an assortment of different rasps to get the job done. I carved a small dent for the thumb and index finger to sit around. I also added grooves on the back for the other fingers to rest in. After I was done rasping, the slingshot was very ergonomic and I moved on to metal files and sanding to remove some of the deeper scratches.
Step 7: Tips
When you are rasping plywood, you can easily break off parts of the edges. To avoid this, rasp very gently near the edges and clamp the slingshot low in a vice.
Step 8: Bands
I found my bands from a very old slingshot that was broken but the bands were still in good condition. To secure the bands, tie smaller rubber bands onto the ends that connect to the arms of the slingshot. I used a small rat tail file to make a small channel to hold some of the bands. After that, you can tie some strong string just for safety.