What are some hacks I can use to make the best use of my Unbottle bottle?

First things first, great job on being so nifty! For keeping your water cold, fill it up with cold water, as it will maintain the temperature up to 24 hours. For hot drinks, add boiling water, empty it out, and fill it with your hot beverage. The Unbottle bottle will keep the liquid warm for up to 12 hours, depending on how many times you open it.