Hi, I found some cool cases at my local hardware store that I think would be great for yoyos.
So, now I am looking for the right foam and when I find it I need to know how to “cleanly” make the holes for the yoyos.
Anybody?
Perhaps you know of past posts that would shed some light.
Thanks in advance,
yokaiyo
Actually there are several really good tutorials on youtube as well as most all yo-yo forums.
Basically you take a can of tomato paste (very small can - just about 2 inches in diameter), saw off one of the ends using a hacksaw to cut it and a ridge on the can as a guideline to keep your cut straight across.
After that, take your can and dip it in some soapy water to lubricate it. Then pick a spot on the foam and push the can gently down into it while turning the can clockwise. Keep doing this gently until you cut through the bottom of the foam. When you do, rotate the can clockwise (yes, clockwise again) while pulling gently upward this time. If you rotate clockwise both ways it will help keep your edges as clean as possible. Repeat the process for however many holes you want to cut, remembering to dip the can in the soap water every 1-2 holes. To dry the foam after you’re done, you can just use a hair dryer if you don’t want to wait for it to air dry. Be careful not to burn or melt the foam though.
Also, make sure that you have another layer of foam backing underneath the layer with the holes in it if you’re transporting any undersized yo-yos (~50mm diameter). The tomato paste can is a perfect diameter for full sized yo-yos, but just a hair too large for undersized ones, so if that foam is free-floating with no backing, they will slide out. I learned this the hard way. No damage though luckily 
Just to save you the trouble of looking it up.
Thanks guys!
yokaiyo
This is the same vid I used. Also on a side note, if you go one size up from the can he uses in this vid, it works great for Offstring throws.