Chris Fix is definitely one of the best YouTubers out there when it comes to learning how to work on vehicles. He gives car issues a simplistic and understandable explanation so you can learn a thing or two while you're repairing your ride. A few months back, he released this video on how to fix a car with a poor idle.
Now, while there can be a few different things that can cause idling problems, it's most commonly an issue with the Idle Air Control Valve (IAC). In his example, he actually has two cars sitting in the driveway. One has an idle that is too high, and the other has an idle that is too low. A dirty IAC was the culprit behind both problems. Chris goes through the process of how to remove them, inspect them, and also clean them so they function properly once again.
The best part about this fix is that the part is easy to remove, and even easier to clean. All you need is some intake cleaner, brake cleaner, or carb cleaner. Shoot the spray into the holes of the part and you should see all the built-up carbon deposits drip out. Additionally, you can use some kind of small brush to help with the removal, but it is not necessarily required to do so. Chris gets some good shots of the spray as it exits to show just how much carbon comes out of this small engine part.
Finally, he puts his IAC back on the two vehicles and, sure enough, his issue was resolved. Even if you're not very mechanically inclined, just about anyone can do this repair. Dealing with a jumpy, low, or high idle is never fun when driving your car, so being able to fix it as simply as this is pretty much ideal. No matter what the issue is, Chris Fix has a huge variety of videos on his channel to help us all out.