Pick the item you want to bling and tap on it.
Once it is in place, Select the tab to either decorate with the jewels or paint.
Choose the color and drag it to the item and begin to bling!
Just repeat the process over with the gems and glitter until the item looks exactly like you want it to.
Once your item is complete, tap on the gem at the right of the screen to place your item back in the display and collect your reward.