I just made my first dice tray. One of my pet peeves is having to stand up to see my dice in a dice tray. While I trust all my gaming friends, I still want to see their roll results too.
The 8"x8"x2" acrylic tray was purchased on Amazon at the following link. Some Amazon reviews complain about stickers on the tray that leave glue when removed. The stickers on my tray came off fine leaving no glue.
The inside is self-adhesive felt bought at an arts and crafts store (also available on Amazon). I cut a 8.75" square of felt and then cut 5/8" squares out of the corners to allow the sides to fold up.
I didn't use any extra padding for fear that dice would bounce out easily. I'm happy with the sound with only the felt. The dice make a nice clunking sound so that everyone knows a roll occurred.
I can't wait to use it!
EDIT: I forgot to say... Score the paper on the back of the felt and remove just the center paper square, leaving the paper on the back of the 5/8" sides. Then carefully stick the felt to the bottom of the tray. Finally, remove the paper backing on the 5/8" side pieces and stick them last. Otherwise, it will be very difficult to get everything aligned properly.