Sammiejane,
I apply it alternately in a 4 day rota, inner right knee, inner left knee, outer right knee, outer left knee, so I'm varying the patch of skin I'm applying it to. it's a tiny amount of gel (petit pois) and I just smear it thinly rather than rub it in, which seems to work for me.
I think I've said before I've never had a problem with thinning hair, but my hair is very fine, and always has been and T hasn't changed that. My hair possibly grows a bit faster and before HRT my body hair was reducing - not that I've ever had much anyway, but it seems to grow a bit faster but not really increased compared to my younger years.
HTH,
S