Get all starters
To get all the starters (Bulbasaur,Charmander, and Squirtle), you will need two Game Boy Advances and another Pokemon GBA game. Start with Bulbasaur, then trade it to your other Pokemon game. After that, start a new game. Start with Charmander and trade it. Then, start another new game and start with Squirtle. Keep Squirtle and catch two Pokemon that you do not want. Trade them for the other two starters you traded to your other Pokemon game. You will now have all three starters.
To get the ancient Pokemon Aerodactyl, go to the house to the right of the Museum in Pewter City. Note: You must have Cut. Talk to the scientist and he will give you the Old Amber. Take it to the Lab on Cinnabar Island and let the scientist bring it back to life. It will be at level 5.
It is possible to get Deoxys at an island in which you solve a simple puzzle.
To get Deoxys, go to Island 9 and push the triangle forward. Deoxys will appear.
To obtain Deoxys, you must travel to Island 9. To do this, you need to obtain the Aurora Ticket, which can only obtained through a Nintendo Event, such as Pokemon Rocks America 2004. Bring your Pokemon Fire Red or Leaf Green cartridge to any of the events in Atlanta, Minneapolis, or Seattle to receive the Aurora Ticket. The same goes for obtaining Lugia, Ho-Oh (both on Island 8, requiring Mystery Pass); and Celebi and Mew (details unknown). Note: Ho-Oh can also be obtained via a link to Pokemon Coliseum.
Note: In the Pokemon Fire Red, you will get the attack version of Deoxys.
To get Moltres you need HM4 Strength, HM6 Rock Smash, and HM3 Surf. Go to One Island, and all the way to the right until you reach water. Surf to the north and you will see land. Continue to go north until you hit water again. Then, Surf north again until you reach land. Go up and move the boulders. Continue to go up and you will enter Mt. Ember. Pass the mountain and you will see more boulders up ahead. Move them and you will encounter Moltres, the Legendary Fire Bird Pokemon.
The legendary dog that you get in the game depends on your starter.
Charmander: Suicune (Water)
Squirtle: Raikou (Thunder)
Bulbasaur: Entei (Fire)
To get all three Legendary Dogs, get together with two friends before any of you start the game. Have one player get Charmander, another get Squirtle, and the other get Bulbasaur. Each of you will get one of the legendary dogs: Charmander, Suicune; Squirtle, Raikou; and Bulbasaur, Entei. Once each of you has their own dog, trade one dog for another. For example, player one's Suicune for player two's Entei; player three's Raikou for player one's Entei; and Player three's Raikou for player two's Suicune.
To get your first Pokemon from the Johto Region, defeat the Elite Four. Go to Island 3, then go in the tunnel. Talk to the man and he will give you a Nugget. Go out the door, and there will be a small patch of grass. Walk around in it, and you will find your first Johto Pokemon.
Note: This trick will only work on Pokemon that have a gender. Either male or female will do. For example, if you want a friend's Charizard but you do not want to trade a level 100 male Venusaur for it, catch a Ditto on Route 13 to 15. Take both your Venusaur and Ditto to 4 Island to the old couple and breed them. The next morning you will have a Bulbasaur egg ready to trade. This can be used to get all the evolutions of Evee. Note: This trick will not work on Mewtwo or most of the legendary Pokemon.
Use the following trick to easily reproduce rare Pokemon, such as Charizard, Lapras, etc. Capture a Ditto in Pokemon Fire Red or Leaf Green. These can be found in the cave at Cerulean. Transfer your Ditto to Pokemon Sapphire or Ruby, then take it to the Daycare couple in Mauville and leave it there. The quickest way to get an egg is to cycle back and forth a few times in front of the Daycare Center until the old man comes out of the gate. The egg he gives you will hatch into the first evolution of whatever Pokemon you put into the daycare. For example, a Charizard will give you a Charmander. Trade with friends to get the other starters, breed an egg, then trade back. The hatched Pokemon will have you as the original trainer.Some Pokemon will not breed in this way, even though they have a gender (such as Latios and Latias).
Volt Tackle (Thunder): Power: 120, Accuracy:100, slightly hurts the user. Black Belt
After you get to One Island, travel up the path called Kindle Road and go towards the volcano. Along this route, you will encounter several trainers with Fighting-type Pokemon. Have your Pokemon use Thief to steal a Black Belt from each of the Pokemon. After you have a Black Belt, take it off your Pokemon and use the VS Seeker to fight the opponent again. Steal another Black Belt from his other Pokemon. Every Fighting-type on this route is equipped with a Black Belt, which boosts the power of all Fighting-type moves.
To get more Rare Candies, look for some Meowths. You are 30% likely to get one.
Follow through Viridian Forest, go to Brock (the first gym leader), and defeat him. Brock has three Pokemon: Geodude level12, Onix level 14, and Geodude level 11. Then, go to the path that leads to Mount Moon's base. Try to go past the man standing slightly past the entrance. He should stop you. He is Professor Oak's assistant. After talking to him, he will give you the Running Shoes.
Your aide will give you the Running Shoes after the first gym.
Go to the Naval Rock Island (if you have the Mystic Ticket), and to the location where Ho-oh confronted you. Use the Itemfinder and it will automatically dig up the Sacred Ash, just like the Macho Brace at Viridian Gym after Giovanni left; and the Top from Pokemon Tower after Mr. Fugi left.
Celedon City: Easy slot machine wins
Use the slot machine at Celdadon City that is at the top in the row you face when you enter. It seems to be easier to get triple sevens if you can time it correctly.
An easy way to defeat Giovanni in all battles is to use a Water Pokemon with Surf on all his Pokemon.
Get to One Island
To Get to One Island, defeat the Cinnabar Island Gym Leader, Blaine. When you come out, Bill will take you to One Island and give you the Tri-Pass. This will allow you to return at any time by taking the Pass to the boat dock in Vermilion City.
Get to Saffron City earlier
This trick requires two Game Boy Advances, a link cable, a Pokemon Ruby or Sapphire game with a "Fresh Water" in the pack, and a Pokemon Fire Red or Leaf Green game that is completed and able to trade with Pokemon Ruby or Sapphire. Also, you will need another Pokemon Fire Red or Leaf Green cartridge. Give a Pokemon a Fresh Water. Trade the Pokemon from Pokemon Ruby or Sapphire to the completed Pokemon Fire Red or Leaf Green game. Take the Fresh Water and attach it to a Pokemon not from Pokemon Ruby or Sapphire. Trade it to the other Pokemon Fire Red or Leaf Green game. Give the Fresh Water to the guard. You can now access Saffron City easier. You can also do the same thing without the Pokemon Ruby or Sapphire cartrigde. Also, it works better when you have the completed cartridge and your friend has the unfinished game.
Get to Sabrina without battling any trainers
This is a long process, but it is the easiest way. Go into the first square, then go up, down, down, up, down, up, up, down, down, up, up, up, down, then down and you will be there.
To get easy money, use a Meowth with the Pay Day attack in wild or trainer battles.