Spray tans and water don't mix -- at least, not right away. When you step out of the spray-tanning booth, you won't immediately notice the bronze glow you desire. Instead, you have to give the formula time to penetrate your skin -- a process that can take a full day. Wait at least 4 hours after your spray-tanning session to shower, then carefully choose your skincare products and treatments to extend the life of your tan.

Mystic Tan suggests waiting at least 4 hours after spray tanning; if you shower before the 4-hour mark, you risk minimizing the intensity of your faux tan.

Waiting to shower 8 hours after your spray tan is ideal, however. This timeline ensures that the DHA has thoroughly absorbed into your skin, because it continues to penetrate after your spray-tanning session ends.

When possible, wait overnight or up to 24 hours before showering; this may help you achieve the greatest results, according to Norvell. The longer you can wait, the better.

Delaying a shower after spray tanning helps you create that bronze glow that you desire. Your sunless tan isn't instant -- it will first appear 4 hours after your session, and the color will continue to darken for another 24 hours or so as the DHA is absorbed.

Additionally, when your body temperature rises as you sleep, the color will more deeply penetrate your skin. As a result, sleeping on freshly spray-tanned skin can intensify your color.

When you do take that first post-tan shower, keep it simple. Rinse with lukewarm water only. The cooler the water, the less likely it is to strip off your new tan.

Avoiding soap is another important aspect of that first shower. Soap has a high pH balance, which can hinder the development of the DHA into a rich tan, according to Norvell. Rinsing with water alone, then, gives the DHA even more time to penetrate your skin.

Both Mystic Tan and Norvell report that their spray tans last about five to seven days. Smart skin care can help you extend the life of your spray tan.

First, shave infrequently because doing so can diminish your color. Likewise, avoid exfoliating with a spray tan because it can scrub and buff away your tan. When drying yourself off after a shower, pat the skin gently with a towel, rather than rubbing, which can rub the spray tan off. Finally, opt for mild, pH-balanced shower gels and moisturizers, as these products are less likely to strip your skin of its color.