How to follow up after a job interview without being annoying

For many people the entire job interview process can feel like blind dating: Do you like them? Do they like you? Is there a future? And just like with dating, even if that first meeting went well, it's totally possible to screw it up if you follow up in the wrong way. With job interviews there's a well-known way to make a good impression: send a thank you note, and a sure-fire way to sour a good thing: annoy the hiring manager by checking in too frequently or too aggressively. But there is still a lot in the process that can be confusing: What exactly should your thank you note say? How long should you wait before checking in? What if you get another job offer?