Protect your workspace and prepare the coaster mold (this is for a single).
Mix 2 oz of resin according to package instructions using the proper ratio of resin and hardener. Divide the epoxy resin evenly into disposable plastic cups.
In one cup, add a pinch of a blue glitter, in the second, add a pinch of a different blue glitter, in the third, a pinch of another blue glitter. Stir each cup slowly until glitter is combined.
Pour each resin mixture into the mold slowly, in a swirling motion, only pouring a little of each color at a time. Layer the colors and use a craft stick to gently swirl the colors together. Let set for two minutes.
Use a straw, heat gun, or torch to carefully remove bubbles from the surface. Alternatively, you can exhale on the epoxy resin or blow through a straw. Leave for five more minutes, see if any additional bubbles appear, and repeat.
Let the project cure for 24 hours before removing from the silicone mold. They will be fully cured in 7 days. At this time you can add clear bumper feet to them if you like.