I love painting still lives. I can arrange them hundreds of times and take numerous photos of them and then troll through the photos cropping and adjusting until I get the perfect composition.
So 'apple' was my first thought for A. Too easy! So I made myself google 'nouns beginning with A' just to see what else was out there and here's what I found that sounded interesting.
apple, accordion, acrobat, afternoon, agave, alcove, alpaca , ankle, avocado
Plenty of themes if I get bored with Apples. Here is my warm up exercise.