I’ll answer from the time when I considered myself a CD.
At first it was only when time allowed – a few times a month. When my gender dysphoria became stronger, I underdressed every day. I stopped underdressing when I began to realize I was more than a crossdresser. Underdressing had become frustrating because I wasn’t being my authentic self. So I amped up my therapy and went back to dressing whenever I could. Fortunately, by then I was able to blend in. My experiences were less frequent but more fulfilling. That’s how things stayed until I decided to transition.