Cheats And Tips

Not much yet but I'll get more

FIGHT SAFARI POKEMON ELSEWHERE
To fight Safari Pokemon in another area, you have to go to the Safari Zone and run into the Pokémon that you want to fight somewhere else. Then go east of the Sea Foam Island and surf up and down. You will get to fight the Safari Pokémon that you ran into earlier. This will give you a better chance to catch the hard-to-get Safari Pokemon.
NOTE: This will only work on certain Pokémon.

LEVEL UP AND MISSINGNO
In Cinnibar Island, equip a flying Pokemon and then fly to Viridian City. Then talk to the guy drinking his coffee that shows you how to catch a weedle. Fly back to Cinnibar and then surf up and down the right side of the island. You'll run into MissingNo,Golbats, Snorlax, Clefable, Kingler and more  at very high levels. Once you defeat a MissingNo. you'll get tons of exp. points!
NOTE: IF YOU CATCH MISSINGNO IT MAY MESS UP YOUR SAVED GAME. IT HAPPENED TO ME BUT IT TURNED OUT FINE.

GET 99 OF AN ITEM
To get over 99 of an item you have to do the same MissingNo trick again but you have to have the item you want duplicated in the sixth from the top in the list. Then fly to Cinnabar Island and surf up and down on the eastern coast. You'll fight MissingNo. but dont catch it, make it faint. Then after the battle, check your items. ( next to the item it will have a weird symbol and a number) You'll have over 100 items! You can do this to the rare candy item and then you can turn each of your Pokemon into level 100 each!

MASTER BALL CHEAT
When you throw a great ball, hold up+B. This will make it act
like a master ball. This only works 90% of the time.

SECRET COINS IN THE GAME CORNER
There are hidden coins lying around in the game corner. You can pick them up by pressing A while walking around. Behind the bookshelf has 100 coins!