This is mostly good advice, but this part is not: > Go into grad school and pursue a PHD because you've got a burning desire to turn one of your good ideas int

This is mostly good advice, but this part is not: > Go into grad school and pursue a PHD because you've got a burning desire to turn one of your good ideas into a breakthrough. If you don't have such an idea based on your undergrad experience, that's already a warning sign that you shouldn't just go to grad school. When this happens, I think the person usually realizes the idea is too naive, too small, too vague, too already-studied, etc. to be a good research problem. It generally requires quite a bit of PhD time before even being able to recognize a good idea, and more to have one. Also, most good ideas simply don't lead to breakthroughs; they lead to nice advances at best. I agree it's a very good idea to know which professors you probably want to work with when you apply. So a burning desire to become expert in a specific area is a very good indicator for a PhD.