1. Kill Cows at Lumbridge and earn Cowhides
2. Go to Al Kharid and talk/trade to the Tanner
3. Tan your hides
4. Buy a needle and threads
5. Use the needle on your tanned hides
Other ways to train Crafting
Use a chisel on Uncuts, uncuts can be earned by monster drops. Many monsters drop them, you can also buy them off players.
When your a higher level you can tan Green Dragon hide, which you can earn from Green Dragons, and Black Dragon hide etc.
You can make your own amulets, rings, ranger d'hide, etc.