1) Spray Deodorant - For Your FEET! Everyone I tell this to is like... duh, why didn't I think of that?! This can be a sandal lifesaver. Most of our feet sweat, there isn't anything wrong with that, but warm days and no socks to absorb the moisure... Just spray a little on you feet when you are sitting down... let air dry a little bit and you will be all set to have significantly less stinky feet by the end of the day.
2) Regular Old Deodorant (Not a gel or spray) - Use it for those pesky red bumps from shaving your bikini area! It helps to make them disappear. You can feel just that much more confident in that swimwear!
3) Comfy Flip Flops - Most people know this, and LOVE a good comfy flat, but I am surprised how much we get "i can't stand stuff between my toe" you probably need to find a more quality pair to try if this is something you say every year. The cheap ones, can murder your feet, so got to a better made shoe and you will be golden.
4) Everything tote - You need a bag that can haul all of your needs for summer, wether it is canvas or a softer synthetic leather, you always end of needing one, so make sure it is in your closet for when you need it.
5) Sunglasses - Not only should you protect your eyes from the sun, you can look darn good doing it. Plus you can wear these pretty much everyday so, you can really get your cost/use to nearly nothing. :)