I like to be between 20-25 ft, all depending on the cover behind you. Does not matter if the deer can not smell you if he can see you. You can never "hunt the wind" as some would say(IMO). The wind shifts, upper thermal and lower thermals. Sometimes the deer just walk behind you and downwind, any scent control would be good. There are a lot of good ideas on this site. I always keep the wind in my face and have certain stands for certain winds. Seems to work for me.