Things most important to consider when doing PhD:

1. Your supervisor-Make sure to have a very credible supervisor who's willing to take the journey with you. PhD is not a short journey. It's a long one and requires a lot of sacrifices. Having a good supervisor is very important. He/ she is the one who will supervise and make sure you stay on the line throughout your research.

2. Research grant- A continuous funding to your research is very important to keep it going without financial problem that will certainly bump your research progress.

To know whether the professor is good or not, always look at their recent research activities and publications. Check their background and how they treat their students by asking current students/staff.

Before beginning phD journey, ask yourself whether you really want to do this or not. Ask yourself whether research is for you or not.