1) First and foremost, buy a bikini top that fits you. Not one that you want to fit you, or one that you hope to someday fit into. Same goes for the bottoms. Keep yourself in check and buy the size that flatters your body, not your ego. In the right size, you will look better and feel better.
2) Stay away from string-tie bikini bottoms. When tied, they sit on your hips and squeeze the skin which can be uncomfortable and unflattering. Plus, the strings can end up leaving weird tan lines! Go for hipster cut bottoms instead.
3) Always have one basic black bikini and one bright colored bikini! There is a mood and occasion for both, so it’s best to be prepared with both choices when it comes time to decide which one to wear. 
4) When you put on your new bikini, or dust off an old one, repeat three times: “I am so grateful I can be out in the sun today and be free.” Because that is what summer is all about. It’s not about your body, it’s about your freedom. So go have some fun!