In 2015, Waimanalo Bay was voted the #1 beach in the America (drbeach.org). It offers one of the most stunning backdrops for pictures, with miles of white sand and turquoise waters. Located in the North East part of Oahu, it is around 45 minutes (15 miles) from Waikiki. Aside from the amazing scenery, Waimanalo Bay also has a forrest area adjacent to the beach which offers two types of environments at one convenient location. Waimanalo Bay is generally not very crowded, parking is very easy and there are also restroom facilities if needed. Our island trade winds typically travel from North to South so it tends to be windier than other locations. If you have long hair, you may want to bring a hair band or have it pinned up.
Although Waimanalo Bay generally photographs well at any time of day, I would try to avoid midday since it can be hot and uncomfortable. The colors will be more vibrant in the morning and early afternoons, while the beach will be in the shade by the late afternoon / early evening. This allows for a very comfortable environment with a slightly washed out background.