Pop off the top and remove all Tru-Fit inserts but leave the metal plate in the base.
Review the Tru-Fit insert colors and pick the one that best complements your collectible(s). Place your collectible(s) on top of that Tru-Fit insert and set aside.
Replace a few of the remaining Tru-Fit inserts back into the base, above the metal plate.
Place the collectible and insert combo you set aside on top of the other Tru-Fit inserts. Bring the top edge of the base up to eye level to make sure you can just barely see the top of your item(s) above the rim. If you can’t see it, or there is too much showing, try adding or removing another Tru-Fit layer.
Place the top onto the base until it fits snug. You should hear a snap when it’s properly sealed. Your collectible(s) should fit snugly against the top to avoid rattling. If it doesn’t, re-open the coaster and add another Tru-Fit insert and then re-close. If you’re forcing it to close, and you don’t hear a snap, try removing a Tru-Fit insert and then re-closing.