Although I don't use Androfeme but testogel - I was initially advised to apply to inner thigh as the skin is thinner there. Due to some side effects I later changed that to inner knee and now as sheila99 does, I apply to soft part of foot instep where the skin is thin.
The main signals that it is working would be restoration of libido ( at least response anyway

) and generally more oopmh, less fatigue and aches/pains after exercise (provided of course that oestrogen dose is sufficient...
Hurdity x