go to heartome city then battle the gym after you beat the gym leader Cynthia will give you a egg.
the easiest way; in hearthome city, talk to a fat hiker and he will give you an egg and when that hatches then it will be a happiny.
It's a thing of luck, you have to be very (un)lucky to get a bad egg. The easiest way is to use an Action Replay.
trade it.
the easiest way is to hack.
With a Budew.
Battle every trainer you see
The easiest and only way to get a lucky egg in Pokemon Fire Red is to catch a Chansey and hope it has one. The best place to do this is the Safari Zone.
use hypnosis after taking its hp down
unlock all other trophies in a game
the easiest way to get were egg is to type /join vampirewar and kill vampire knights they have 3% chance to drop a were-egg
You can put Charizard/Charmeleon with Ditto (The easiest way) in the Daycare and they'll lay a Charmander Egg.
Either cheat or "chain" 40 pokemon.