Wherever you think the scent will project the best is where you want to spray or dab the scent. It really doesn't matter where just don't go overboard with the Versace scent ! haha. Also, if you have the bottle without the spray you could use a cotton ball and apply the cologne with that instead of getting it on your hands.
What up Metalica ! For the summer, I'd say no more than 3 sprays.. 1 to the middle of your chest, and one to each forearm. Make sure you have a nice amount of space between your skin and the sprayer to cover more area per spray and so it can develop quicker since the opening is quite harsh. Also give yourself at least an hour before you go our so you know how long it takes for it to develop to the drydown on your skin. Repeat the same process for winter, except for 2 sprays to the chest in different areas.