Step 1: Exfoliate. This rids the body of dead skin cells. The reasons tans fade is because layers of your skin flake off. You want your base tan to be on the freshest part of your skin (ew!) to ensure that it lasts as long as it can. My person favorite exfoliator is The Body Shop Coconut (or any flavor) Body Scrub.
Step 2: Pick your time and place. The best times to lay out are between 12:30 and 3. Try to lay near water because the sun will reflect off the water and onto you. Wear a black bathing suit as well this will attract the sun. I try to lay out 2-3 times a week for about a half-hour to an hour per session.
Step 3: Grease up. This is the fun part. Tanning oil will help create a better tan because like I mentioned before, the sun reflects off of the oil. This means, the more glistening your skin is, the more light will attract (think a prism). Depending on your skin tone, you might need an oil with 10-15 SPF for pale skin, 2-5 for fair/medium, and if you're olive/dark like me, you can go with no SPF. If you really are feeling brave, olive oil makes an AMAZING tanning oil, but I warn you that it will fry you. Continue with caution. Also, aside from the oil, make sure you put at least 20 SPF sunscreen on your face. This will prevent future wrinkling and present freckles. The way I see it, you can always add bronzer to your face if it is lighter than the rest of your body, you can't exactly bronze your body. Also, remember your lips can burn. Use LIP BALM NOT GLOSS to prevent flaking. Gloss, like tanning oil will attract the sun and burn your kissers. The products I like are Hawaiian Tropic Dark Tanning oil, DHC White sunscreen, although you can use any, I just have sensitive skin, Panama Jack Full Sun Tan Accelerator for my first few times laying out, and my EOS egg balm for my lips.
Step 4: Don't forget the hair! Personally, I have dark hair and I like to keep it that way, so I wear a turban on my head when I lay out. Whether you want to protect your hair from the sun is up to you, but I still recommend using a deep conditioner as you lay out. The one I like is Garnier Fructis Deep Conditioning Mask.
Step 5: Hydrate! Keep in mind, the more dry your skin is, the less your tan is going to stay on. This means hydration on the inside as well. Don't forget a water bottle, or other hydrating drink. My personal favorite is Vita Coco Coconut Water. Makes you feel like you're on an island as well.
Step 6: Recover. After your little sun date, MOISTURIZE and keep moisturizing every day about twice a day. Make sure it is a high quality moisturizer too, make sure there is no alcohol of any kind in it. Alcohols in moisturizers will strip a tan off your skin. Right after sun, I use Hawaiian Tropic Silk Hydration in Coconut Papaya. Then, after I shower and for the rest of my moisturizing, I use Body Shop Coconut Body Butter. Fair trade, no alcohols, great scent, great results.
If you follow these steps, I promise your tan will be radiant all summer. However, I do not know how every one's skin tones are, so if you are the type that burns, use more SPF, stay hydrated and cut your duration shorter. Happy sunning!