for me, I started dressing when I was 5 years old. Far before any hormones kicked in. My testosterone levels are normal for my age. So I do not really think hormones has come in to play at all with my dressing up.
The biggest factor has been with my current wife being accepting of my dressing which has given me opportunities to expand my wardrobe significantly. I think we all wonder what is different about us compared with other males as to why we desire to dress up.