I've thought about reviewing other items, but lingerie reviews just seem easier to me.
I start by taking a metric buttload of pictures. Even if you don't want to post them, they give you ideas for what to put in the review. I take pictures of the packaging, me in the garment, the garment on the floor, anything that came with it....whatever. Seeing the pics helps trigger thoughts you have on the piece, or sometimes helps you see things you would've missed otherwise (like in the wild night corset review. I didn't even realize the grommets were uneven until I saw the pics).