Achieving even layers: To ensure that each new layer of gelatin liquid spreads evenly across the entire pan, you may need to tilt the pan slightly.
Chilling time: The layers of Jell-O will set up rather quickly because they're so thin. At first, the layers may be set in as little as 10-15 minutes.
To make thicker layers as I did for the Fourth of July Jell-O Salad:
For each clear layer, use 1 entire box of Jell-O with 1 cup boiling water. Similarly, for each cloudy layer, use 1 entire box of Jell-O with 1 cup boiling water, plus 1 cup vanilla Greek yogurt and 2 tablespoons cold water. You can choose any colors you'd like, depending on the holiday or your party's theme colors.