Using this carrier bag is a breeze. First, adjust the strap to your preferred length and put it on. Then, place your 40oz tumbler or water bottle in the main part of the bag. You can store your phone, keys, ID cards, and bank cards in the detachable pouch or the small pocket. When using it in the car, you'll find that the tumbler fits well in the cup holder even with the bag on. As for maintenance, use a damp cloth to wipe the bag clean if it gets dirty. Avoid using harsh chemicals as they may damage the polyester fabric. Also, keep in mind that the color of the actual item might be slightly different from the preview images due to lighting during the photoshoot or your monitor's display.