How Should I Incorporate Retin-A Into My Skin Care Ritual?

hi i would like to start using retin a micro into my skin care ritual. i would like to know what strength i should use for BEST results and if what area i should use it on for antiageing benefits. do i use completly around and over the eye lids too and what about my neck area? and will a pea size really cover all that area. i havnt had luck with the cream formula using pea amounts. and can i use it if im having laser beard removal treatment? im fro australia and want to buy it online.