Process can be gauged by breast development, fat distribution, facial changes, body hair distribution, etc. You don't need to measure T levels. The degree of T action can be determined by looking at how oily vs dry your skin/hair is, body odor, body hair thickness/color, increase in subcutaneous fat, decreased muscle mass/strength, less spontaneous erections, decreased libido, shrinking of testicles, amount and thickness of ejaculate.