An oldie but a goodie: what you have in your portfolio is what you’re going to get commissioned to do.
A couple years back, I did this personal project of a cityscape and posted it on my website. Soon after, my first building related commission came in and now that’s what everybody wants from me. Now I’m trying to steer away from that and am drawing animals and plants.
Having a profession on “both sides” has taught me a lot about that too: working as a designer who commissions and as an illustrator who gets commissioned. When I’m art directing, the only thing I see is what’s in someone’s portfolio.
It rarely crosses my mind that this person would want to do something else than what’s presented in his or her portfolio.