Research can also be performed at companies. Though this option is most common for natural scientists, large corporations sometimes employ historians who work on company history, while PR consulting firms may employ humanities graduates for of their strong writing skills. So it is worth while to think outside the box.
The typical sectors for finding work vary by field. Biologists often find jobs in the pharmaceutical industry for example, while banks and insurance companies may employ economists, and social sciences and humanities graduates are needed in education.
Regardless of field, extra qualifications like leadership ability or interpersonal skills will almost certainly be required. Find out what skills are relevant to your chosen field, and make sure that you supplement your doctoral studies with appropriate courses and respective experiences.