After max hp, people usually put 1 point in corkscrew, work on mastery, and then either go lightning charge or energy charge. I personally went lightning charge because truckers are weak to lighting, as well as some of the monsters in mp3. Two training spots I planned on being at for a while. After lightning charge, you can move on to energy charge. Or you can do the opposite, and max energy charge before lightning charge, its a matter of personal preference. Also, it wouldn't hurt to put some booster in the middle of that somewhere. And if you really want, you can add to energy blast before lightning charge if you don't plan on training on any lightning-weak monsters at all.
Later on you'll have to make a choice, whether to leave booster at 11 and max corkscrew, or max booster and leave corkscrew at 11. At level 110 you get Speed Infusion, which requires you to have max booster. The people who don't max booster in 2nd job tend to use 3rd job SP to max it. I don't see why anybody does this, but it seems to be a popular choice.