Aperture was a challenge for me. I struggled with whether to zoom or not to zoom, using my proximity to zoom, and remembering that the depth of the background really makes a difference. Sometimes I felt like I had to be either standing very close to my subject to get results or be very zoomed in to get results. Anything in between didn't work for me.
I tried pictures of my dog and horse first and could not get a good blurred background so although I am not thrilled with all my subjects, I felt like taking these gave me a chance to work on aperture. They are taken on my Canon 350D with a Tamron 28-200mm Macro lens all on manual focus.