What to Look for in a Fragrance-
When looking for scents, you want to go to the closest mall or fragrance outlet and try a bunch of fragrances. Learn how they work, perform and smell. Don't be afraid to take a free sample if they offer them. Also discover what makes you like and dislike certain scents. Research the scent on this website called Fragrantica. Fragrantica shows you the performance, wearability, notes, reviews, and other very useful info. Research what enthusiests think are really good buys because there isn't a huge selection at the mall. Things to consider is how long it'll last. I recommend something that'll last all day or at least 8 hours and projects enough so that others can smell it when they're close (moderate-strong projection). Figure out what situations or seasons you want to wear a scent and what notes you like. Then go out and buy it at a mall or online. 2-3 colognes is enough but you can work up to around 5-8 for more variety. You must have at least one summer and one winter scent. If you only want one fragrnace, then get a signature scent that can work all year in any situation. I'd say no more than a full retail price of $150, and $120 from a discounters. I think the sweet spot in the best bang for your buck is between $45-$80 (discounted prices).
Where to Spray and How Many-
Everyone has their own strategies as to where they apply colognes, but there's places on your skin that're better than others. With strong scents, I'd spray under the corners of your jaw, once on both sides. If you want you could add one either on the back of your neck or bottom center of your neck. About 2-3 sprays, so you don't overwhelm others around you. If the fragrance is weaker, then spray both sides of your neck, the lower middle of your neck, and maybe one of each end of your forearms. So a total of 5-6 sprays. If you're outside, there's more room for the scent to travel. Inside, the space and temperature is more controlled so it's easier to smell. Spraying on clothing doesn't project much at all but can last for days, so I wouldn't alwasy recommend it.
Discounters are your Best Friends-
Discounters are online websites and companies that sell fragrances below their retail price to the point where they almost feel like scams. If you shop in the right places they'll be 100% authentic and not fake. I recommend places like Jomashop, Fragrance Net, and Fragrance Buy. These places have great selection on fragrances that you can't find at the mall and different sizes too. Newer fragrances are hard to find here and they don't have everything. Blind buying can help you find great scents that you can't find in person with the risk of not trying it first, so do your research and know what you like.
Concentrations-
The concentration of a fragrance is how much of the oils and ingredients is in the liquid in contrast to alcohol. There are many different kinds of concentrations, but I'll focus on the main 3. There's eau de toillete or EDT is the lightest. It's typically weaker and not last as long than the other two I'll mention. However there're fragrnaces that are EDTs that are very strong. Then there's eau de parfum. EDPs are more medium in concentration and last pretty long and have a medium projection. Lasty parfums, they're denser and often very strong compared to other concentrations.
Storage-
Fragrances are expensive especially when you own a lot, so you got to take care of them. Keep them away from heat, sunlight, and moisture. Storing them on the bathroom sink isn't recommended. Put them in a cabinet, or any other dark and cool area. Cologne contains alcohol to help them last, so obviosly exposure to fire isn't a good idea. This will allow a fragrance to expire. Also the lower the concentration, the longer a fragrance will last. Fragrances typically expire around 5-6 years.