There are several companies that make pattern drafting software for the home sewer. This software requires you to input an accurate set of measurements, make some basic design choices, and print out your pattern on your printer. These programs do require some work to get accurate measurements to begin with, but are worth it in the end to get custom fitting patterns.
Personalized pattern drafting services will create custom patterns for you. The pattern is drafted to the specific measurements you supply. This is a good option if you cannot find a pattern to fit and do not have good pattern alteration skills.
Hand drafting patterns can be fun. You can learn this skill at a workshop or community college. There are many books that also give detailed instructions on pattern drafting. Even if you don't want to draft your own patterns, this skill will improve your understanding of fit and increase your knowledge and ability to alter commercial patterns.