If you’re not sold on the advantages of letting another human being take your portrait, this leaves you with one option: self portraiture.
There is a big advantage in being both the photographer and the model: you don’t need to read between the lines, you know when the subject is tired, uncomfortable or hates a particular shot. You also don’t need a release.
When I suggest doing it, most people come up with the following set of excuses:
1. Easy for you to say, but I’m not photogenic
2. I tried, but the photos sucked
3. It feels stupid