What might I do next time to get a "less sterile looking" effect?
I think you could try lighting the flower other than the way you have done, which seems to me to be full frontal lighting.
You could try side-lighting and back-lighting for starters. You could try to get some shape and texture into the petals.
At present, the petals look flat and uninteresting.
You could also try filling the frame more and avoid the dead-centre, front-on placement.
Roger