Part of what makes the beauty industry so enticing is that it doesn’t come with a rule book. You can create whatever shape you want with eyeliner, pack on whatever eyeshadow color combination you feel drawn to and style your hair in a way that makes you feel good. But while makeup and hair is all about free expression, some other beauty practices are less forgiving.

Case in point: spray tanning. How you prep your skin before a spray tan and how you care for it afterward can make or break your finished result. And, because spray tans take several hours to develop, there’s plenty of room for error, making it that much more important to follow specific protocols.

You may already be aware of basic spray tanning instructions, like exfoliating before your appointment, moisturizing daily to extend the life of the tan and avoiding things like deodorant and perfume on the day of your spray tanning session. To find out more about the unspoken rules, HuffPost spoke to several spray tan artists to learn how you can ensure a glowing, even tan.

After giving your spray tan several hours (or overnight) to develop, the initial water rinse is crucial. During this time, you’ll see the brown color being rinsed off and what will remain on the skin is the faux tan.

Brittney Bennett, a spray tanning artist and the founder of Be Bronze Studio in Los Angeles and Arizona, said to avoid peeing in the shower during this initial rinse.

“The acid in your urine could cause streaks running down your legs, which will be apparent once you get out of the shower,” she said. “If you find the need to pee in the shower, you should wait until after the water runs completely clear.”

If you’re looking to reap the full benefit of your spray tan, consider scheduling your appointment around your menstrual cycle. Your menstrual cycle is a time of fluctuating hormones, which affect your skin’s pH level and moisture levels. This can affect how well the tan adheres to the skin, which means your tan may be lighter and more likely to fade quicker.

Your best bet is to schedule your spray tan well before or after you’re menstruating. If you must get a spray tan while on your period, Bennett said you can ask your artist to adjust their solution accordingly. “I either place the client in a little darker of a solution or have them keep it on a little longer before rinsing,” she said.

Bennett said to avoid funny business of any kind before you do your initial rinse. “Think of your spray tan bronzer as wet cement — if you put your hands in wet cement, there will be marks in it when it dries,” she said. “Time and time again, I have had clients have streaks or light marks on their [body] due to things like sweating during sex.”

Courtney Claghorn, the founder of Sugared + Bronzed, a sugaring and spray tanning studio, agreed. “To avoid smudging your spray tan and getting odd patches, you should avoid all skin-to-skin contact until your first shower,” she told HuffPost.

“Over the years I have seen so many clients who have just showered prior to their appointment and I have to remind them that this is not ideal,” Bennett said. “Not only can the products you use in the shower create a barrier, but you run the risk of your tan developing lighter due to the altered pH balance of the skin, which is working with the DHA in the spray tan (the active ingredient responsible for tinting the skin).”

For the best results, you should shower 24 hours prior to your appointment and a minimum of four hours before, if you need to shower on the same day.

“Any liquid that gets on you after a spray tan can streak and ruin your chances of an even glow,” Clagnorn said. Avoid things like doing the dishes, watering the plants and steaming clothing — and obviously, rain. “Even minimal splash-back will leave a streak or a lightened spot,” Clagnorm said. “Think of water as an eraser: anywhere it touches, it will leave a spot.”

Isabel Alysa, a spray tanning artist and the founder of Dolce Glow, recommends timing your hair removal wisely. “When you shave, the razor tends to leave behind a waxy residue, which can cause streaking when the spray tan is applied,” she said. “Also, shaving or waxing after a spray tan can remove the top layer of your skin, which can then lead to uneven fading or patchiness on your tan.”

For best results, you should shave or wax no later than 12 to 24 hours before your spray tan appointment.

If you loathe that tacky feeling after a spray tan, a drying powder can help make things a little more comfortable — plus, it comes with other benefits that’ll make for a long-lasting tan.

“A drying powder is a crucial post-spray tan step,” Bennett said. “Drying powder is applied on the top of your spray tan to dry and lock in your tan, eliminate any stickiness and prevent the color from getting on your clothing.”

Wearing a bra, or any tight clothing for that matter, after a spray tan will potentially cause the movement of the cosmetic bronzer, which in turn will cause it to develop lighter or blotchy in those areas, Bennett said. Instead, always stick to wearing dark, loose clothing.

Before your initial rinse, you should avoid all types of workouts that can make you sweat including hot yoga, Pilates and dance class. Claghorn said that sweating will cause streaks of discoloration, which can lead to that dreaded zebra look.

Save any activity that could cause sweating until after your initial rinse. If you find yourself sweating anyway, Claghorn said to immediately use a cloth to gently dab the sweat away. “If you’re starting to sweat a ton, get in the shower, even if it’s not time yet. A lighter tan is better than a streaky tan,” she added.

Sunburns can be equal parts painful and frustrating, especially if you have a spray tan appointment approaching. “If you have even the slightest burn, this is the time to reschedule,” Claghorn said. “If you spray over a sunburn, it can peel and splotch all over.”

Also, Alysa added that spray tanning over a sunburn will do nothing for covering it up. “Some people think the spray tan will help correct a sunburn, but it can actually make it worse,” she said. “Spray tanning solutions have the active ingredient DHA, which tends to cause dryness, so if your skin is already sunburnt, the spray tanning solution will only worsen it and speed up the peeling.”

You’ll save yourself from some pretty embarrassing bikini moments on the beach if you avoid sitting directly on a toilet seat immediately following your appointment. Doing so can cause the bronzer to pull off and stick to the toilet seat, which can cause white areas where the spray tan should have developed, Bennett said.