If you want to smell strongly of your perfume throughout the whole day, the first thing you need to do is choose the right fragrance. As I mentioned in the Projection, Longevity & Sillage entry, projection is a property of the perfume. So even if you spray a lot of a fragrance that does not project well, what will mainly increase is the intensity of the scent, while the area it projects to will only expand slightly. Apart from that, once you have chosen a strong perfume, if you want to smell strongly of it all day, you should take a small decant bottle with you before leaving home and refresh it with 2–3 sprays every 3–4 hours. If you choose a strong perfume, refresh it during the day and apply at least 8 sprays before leaving home, you will smell strongly of your fragrance throughout the day. I wrote this for outdoor environments. If you are going to be in an office, you can reduce the number of sprays you apply before leaving home a little.