Getting Alchemist to 15 for Tricks of the Trade should be a top priority. It's technically not needed for crafting the 1 star and 2 star gear if your stats are high enough (aka, you spent a few hundred thousand on materia), but it's one of the best general purpose crafting abilities in the game. Alch to 15 is the first thing I'd recommend any new crafter do. Culinarian to 37 for Steady Hand II (and Hasty Touch along the way) being the first non "take it to 15" thing that's recommended if you want to set yourself up for long term crafting. Also not required, but having Steady Hand II is pretty nice.