I started on Testim, but the application is basically the same. It is a lot of gel regardless of how big you are

The instructions are primarily worried about the transference, BUT those areas of the body apparently absorb better than others. So I would make an effort to get the majority of your daily dose applied there. Whenever I had excess, I would rub it on my sides and stomach. I've heard other people put it on their thighs.
My doctor also recommended applying after a shower, on the basis that your pores are more open then and the absorption rate is higher. I don't think it matters too much if you skip a shower. I've taken the stuff camping before and just applied it daily even without showering or getting wet. My T levels have been very consistent, so I don't think it'll have any kind of affect if you skip a shower once a week or so.
I started getting changes within a week on a half dose, so you should be well on your way to Hulkdom soon