Try to carry around as many Pokemon that have the ability Pickup as you can. Tis is useful at the start of the game. Before playing the game, a good idea is to decide what your team is going to be. As you go along in the game, carry around those Pokemon. Since you get more good Pokemon later in the games, you can fill your team with Pokemon like Meowth, Phanphy, Zigzagoon, and Pachirisu until you get the Pokemon you want for your final team. These are Pokemon with the ability Pickup. After every battle, check to see if they Picked up any items. Don't give them any items to hold. You can get some good items through this, like Rare Candy and PP Up.