Spray tanning is really difficult for alot of people that i know, myself included...Expoliating before hand is ABSOLUTLY nessasary to prevent discolouration. I myself found that if i was going to do the spray tan i first needed a base tan in order for it to not look "fake" whether the base tan is natural or from a few minutes in a tanning bed a day or so prior to the spray...it also makes the wearing off look more natural too. Another suggestion is showering right before you go so that you wash off any excess oil from your skin allowing more of the colour to stick to the skin instead of the oil on your body(give you less chance of it washing away in spots...lol...hope this helped you...Good Luck And Have fun on your Vacation!!