I can't tell you how many times I've stepped on the lid of a paint can as I step back to appreciate my work! I've left my footprint on a rug and had toss a cool pair of shoes from stepping on paint can lids. To avoid this messy step, open and store your paint cans on a drop cloth in the corner of a room and refill your paint trays at that location. Don't forget to quickly cover your paint can between refills to keep the air out and your paint fresh.
Something else to have at your paint station is vanilla extract. A few drops of vanilla extract in your paint neutralizes the smell of paint fumes and makes painting more pleasant.