If you find/given a Pokémon™ egg, keep the egg with a Pokémon who uses electricity, such as; pikachu. It'll hatch much quicker.
Pokemon with the 'Pickup' ability (such as Zigzagoon, Aipom, Meowth, and Lillipup) have a 10% chance of picking up an item after each battle (including wild battles), even if they didn't acutally battle! The items start decent at low levels, and get really good at high levels (including TMs, Max Revives, etc.) However, most of them lose the ability after evolution and they can't Pickup an item if they are holding one. In Ruby/Sapphire, you will always get good items no matter the level.
So, find and carry a Pickup 'mon next time you go train. You will thank me.
try and find shiny pokemon becuse ther the best!
find pokemon on high levels like lv80