There is the project I build for my two years old son. He like playing with all kinds of buttons he found everywhere. But they almost done nothing for him, except the ones on my dryer. So I decided to give him an box full of buttons that take different action on lights and a motor.
Step 1: Choose components wisely
For my son and for many other kids, it's not only what the buttons do, but how to manipulate them and trigger them. So it's a fairly choice to get different types of buttons like one you swap, some you lift, other you pull or push. So I found about 10 types of buttons from an electronic store nearby.
The actions I planned for the buttons is to trigger some lights and one motor. I have chosen leds for almost all of them except for two, because I wanted the box to work with batteries. I used four C type batteries, so the box works a while with this power source.
Step 2: Mesure all components
The best way to fit all components on and in the box is to take some time to mesure all of them.
The holes I needed to place the parts do not needed to be so precise, so I used a compass and a ruler. Otherwise I would have been purchased caliper.
Step 3: Plan where to put the parts
I used a vector drawing software to create the plan where I would and could place all the buttons and the other parts. This step can be done by hand on a paper, but it's much faster to do it with a drawing software. It's possible and easier to move parts to fit them along each other. Especially because it's not much difficult to place part on the surface, but it's harder to think of the space they take inside the box.
Step 4: Cutting holes
After I stuck the paper to the box, I drilled the holes. I also use a rotary tool to cut bigger round holes and the square ones.