Here are a couple images to serve as a refresher on where to place you arrow / bullet.
Having a rangefinder that you can set to compute the calculations for you makes it very easy.
The illustration below is of a Leupold Range finder that has the True Ballistic Range feature. There are a number of manufacturers that offer this feature.
The rangefinder in the illustration below is set for older bows with draw weights below 50 pounds. The deer is 40 yards away (Line of Sight), at a 40 degree angle from the archer. The range finder has calculated that effective range is 34 yards.
So what did we do before all these fancy rangefinders? What I did was the old fashioned, pick my tree stand location and pace off a two or three trees as distance guides, climb up the desired height and estimated where my sight pin would need to be based upon previous experience. For longer distance rifle shots, we would estimate ranges based upon experience and take the shot. In other words practice and experience is key. Spending time on the archery and rifle range is also key. Technology may not always be there for you.