Cooking
In order to really maximize your skill gain, you should take advantage of either a Skill Tutor Statuette or a Crystal Ball of Knowledge. It will help keep your training in the "Optimal" difficulty range.
0 - 30: Buy from a Chef NPC.
30 - 100: Cook fish steaks 1 at a time.
0 - 30: Buy from a Chef NPC.
30 - 100: Cook fish steaks 1 at a time.