By Leveling Up:
* Iron Head: A powerful Steel-type move with high accuracy.
* Heavy Slam: A powerful physical move that hits harder against heavier targets.
* Rock Tomb: A physical Rock-type move with a chance to lower the opponent's Speed.
* Earthquake: A devastating Ground-type move that hits all opponents.
* Crunch: A powerful Dark-type move with a chance to lower the opponent's Defense.
* Rock Slide: A powerful Rock-type move with a chance to flinch the opponent.
* Stealth Rock: A move that sets up Spikes, damaging opponents upon entry.
By TM/TR:
* Flash Cannon: A powerful Steel-type special move.
* Stone Edge: A powerful Rock-type move with high accuracy.
* Rock Blast: A powerful Rock-type move that hits multiple times.
* Bulldoze: A powerful Ground-type move that lowers the opponent's Speed.
* Thunder Fang: A powerful Electric-type move with a chance to paralyze the opponent.
* Ice Fang: A powerful Ice-type move with a chance to freeze the opponent.
* Fire Fang: A powerful Fire-type move with a chance to burn the opponent.
* Dragon Claw: A powerful Dragon-type move.
* Outrage: A powerful Dragon-type move that hits multiple times but makes the user confused.
* Superpower: A powerful Fighting-type move that lowers the user's Attack and Defense.
By Breeding:
* Gyro Ball: A powerful move that hits harder the slower the user is.
* Iron Defense: A move that raises the user's Defense.
* Screech: A move that lowers the opponent's Defense.
* Rock Polish: A move that raises the user's Speed.
* Curse: A move that raises the user's Attack and Defense but lowers the user's Speed.
By Tutor:
* Roar: A move that forces the opponent to switch out.
* Rest: A move that puts the user to sleep and heals it fully.
* Sleep Talk: A move that allows the user to use another move while asleep.
* Snore: A move that only hits when the user is asleep.
* Toxic: A move that poisons the opponent, causing damage over time.
* Substitute: A move that creates a substitute for the user, taking damage instead.
Other Methods:
* Magnet Rise: A move that makes the user immune to Ground-type moves.
* Stealth Rock: A move that sets up Spikes, damaging opponents upon entry.
This is not an exhaustive list, as Steelix can learn many other moves through various methods. The best moves for Steelix will depend on its role in your team and your play style.
For more detailed information on each move, you can consult the Pokémon Wiki or other online resources.