People tend to go for similar personality types. Extroverts will tend to be attracted to other extroverts because they're energised by socialising and taking action. Introverts tend to form better relationships with other introverts, because introverts are typically more independent and lose patience with extroverted personality types.
However, in my experience, there are fewer introverts than extroverts, and introverts are often more willing to look beyond their personality types than extroverts are, which leads to a bias that favours the extrovert.
In terms of body types, people will usually be attracted to people that show physical characteristics that match their personality. "How do people tell personality from physical characteristics?" you may ask. Well, here's
a BBC questionnaire that might help to show how this effect with facial recognition, it's not a huge stretch to apply it to the physique as well
TLDR version, if you want to sleep with someone, try to look like them as much as possible!