Sims 2 Strategy: Skilling
If you want your Sim to hit the top of his or her career ladder, the first thing you need to do is get their skills up as quickly as possible. Once your Sim takes a job, there will be precious little time for skill building, so start them early!
Your work as a slavedriver begins when they age to Child. Obviously they need to keep their homework done enough to prevent the Social Worker from showing up. Focus on having your child Sim do just enough homework to maintain a C or B grade. This will leave them with enough free time to engage in skilling.
I find that trying to get child Sims to boost any skill other than Creativity is often an exercise in frustration for both of you. Plant them at a musical instrument or painting easel and let them Creativity the hours away. Some child Sims may enjoy boosting their Logic skill by playing chess or looking through the telescope. If your child Sim protests or gives up on these activities, don’t push it. You’ll have plenty of time to skill them up later in life.
The same essential strategy holds true for the Teen years. Except that teenage Sims seem to be more willing to boost their Charisma by practicing their speech in front of a mirror. (As long as they’re there, you may as well have them use some acne cream.) Teen Sims can also benefit from using the telescope to search for alien life. If they get abducted, it makes them eligible for a college scholarship - bonus!
By the time your Sim gets to college (if you have the University expansion pack) they should be at level 3 or 4 for most of their skills. At this point, you will want to start focusing on the skills you know they will need for their chosen career. For example, if you intend to put them through the Culinary track, you will want to have them focus on studying Cooking. For the Athletics career track, put them on the exercise equipment and max out their Body skill.
There are several ways to increase the speed at which your Sim levels up their skills. The most notorious of these is the Thinking Cap, which is an aspiration award. Unfortunately, if your Sim dons the Thinking Cap while their current aspiration level is less than gold, the Thinking Cap can malfunction and deduct a skill point.
Each career track has a career reward associated with it. If you get high enough in the Business career track, you can get a mini-golf putting green. The Athletics career track nets you a punching bag, and so forth. When your Sims use these career rewards, the associated skill is boosted more quickly than it normally would be. This can be very helpful if you are running a legacy family, since each family member can climb their career ladder and essentially donate a career reward to their heirs.
The speed at which your Sim learns new skills is also partly determined by their personality. Sims with a high Neatness score will pick up Cleaning quickly, while Sims who are slovenly will protest your request. I once had a Sim whose meter was pegged on the sloppy side - whenever I told her to study Cleaning, she walked over to the shelf, picked up the book, then self-canceled the action and put the book back. I was never able to get her past Level 1 in Cleaning. Some Sims just don’t have what it takes!