First, make sure you're holding your arm out to the side, not in front of you. Make gradual movements up and down with your arm, keeping your hand open and your palm facing the camera -- you don't need to bend your body to move further down a list.
Wait until the option you want to select is highlighted, then move your hand firmly straight across your body. Think of swiping across your body to your shoulder or your hip, depending on whether you're selecting a high or low option.
If you accidentally select an incorrect option, put your right hand down at your side and use your left hand to select "Back." Try making your selection a little more slowly this time, and be aware of letting your hand travel higher or lower as you swipe.
If you're playing the game with someone, decide who's going to be the driver and have the other person keep their hands at their sides. If the menu color keeps changing between blue and pink a lot, it means you're playing tug of war with the menus!
Once you get the hang of it, you'll be breezing through the menus without even thinking about it!