Midori-chan
Oh, yeah, there's that trick, too. I use that to keep the parents as adults while the kids grow up. I've discovered that it is insanely easy to max their skills.
First make you sim a knowledge aspiration (you can change this later with the correct reward)
Move them onto an empty lot. Buy all necessities, use move objects on to bypass walls. (okay this will require cheating)
Turn aging off. and use motherlode only to buy the stuff to keep them happy.
Now then you need one of every skill boosting item.
The sim should want to learn skills so let them, once aspiration gets high enough pick up the energizer, use when needed. Also pick up the learning cap, replace when needed. Turn up the speed to max, and just have the sim alternate between learning the skills they want and energizing, they should never get out of platinum.
Once all skills are maxed move out, buy a home get a job and socialize, and use the aspiration changing device to pick the asperation you REALLY want the sim to be.
Easier than it sounds...
sweatdrop