SPF/Sunblock for the face and body - I prefer my SPF to have a factor 50 or more especially for my face. SPF is important to protect your skin from getting burned and also being exposed to the sun without any SPF can worsen any hyperpigmentation that you may have. It is important to find a good and gentle SPF for your face that is light, unscented and will dry matte or dry into powder form because these kinds of SPF will not clog your pores. As for the body any SPF with a factor 50 or more will do.
Tinted Moisturizer or Light foundation - This may not be a essential for other girls with beautiful skin but I have a lot of acne scaring and I am not really that confident to go out the door without any kind of foundation on my face to cover my acne scars. Since it is summer I tend not to go for full face makeup but I make sure that I have a little bit of foundation and concealer on just enough to conceal my hyperpigmentation from my acne scars. I always make sure to wear face primer underneath to keep what little foundation on my face from melting.
Bright Fun Moisturising Lipstick - Since it is summer you can go all out and wear fun bright lipsticks. I like to keep my make-up on summer to a minimum so I rarely wear any eye makeup at all, just my minimal foundation and concealer to even-up my complexion. Wearing a bright and fun lip color would definitely make your lips be focus and this would make you look put together without to much effort. I prefer to use moisturising lipsticks because my lips tend to get dry and chapped during the summer. If you don't have a moisturising lipstick then do not worry. Just use any lipstick of your choice but be sure to put lip balm first before applying your lip color, this would help keep your lips moisturized.
Sun Glasses/Shades - your shades will not only finish your summer look but it will hide the fact that you are not wearing any eye makeup and it will protect your eyes from the harmful rays of the summer sun.
Body spray/mist - it is always important to keep smelling fresh. My favorite summer scent is the cooling mist in "Sweet Pea" from Bath and Body Works.
Enjoy your summer everyone!