UPDATE /7/14 After months of issues with the working state of my Sims 3 game, I was finally able to update the Optional Store Skills mod. Is there one that works for update because I always update the sims 3 launcher when it says to. How to use the Sims 3's Cheats Console to raise skills. There is no direct way to do this without a mod, but you can dramatically speed up the process.
For The Sims 3 on the PC, a GameFAQs message board topic titled "Is there a way to speed up skill progression?". Whether it be through a cheat code or a mod. One thing "FAST Learner" your sim will learn skills faster. Mods: Fast Skills by Shimrod from Mod The Sims These mods increase the speed of skilling on all ModTheSims - Cheap Aspiration Rewards (V4 Feb.3). They changed a field that is responsible for the skill gaining when your Sim has a high mod. This skill gain is now also saved with your game and will never go.
The only way to instantly raise a skill that I know of is with mods, like go to nirocraft.com look up skills in the sims 3 downloads section you.