Working with swimsuit models is no different than working with other kinds of models. And it is different.
It is the same because you need to know your stuff. You have to be able to get good poses, good light, and everything else right. It is the same, because models expect you to not waste their time.
Swimsuit and bikini photography is different because light plays a role in a different way than on a fully clothed model. Also, depending on your purpose, swimsuit may be more sensual in the visual appeal than your other work.
On another post, I will talk about how to find the models you want, but this post is going to be more on working with them and getting the results you want. I will talk some about lighting, but more on general lighting concepts rather than technical details.
Swimwear photos can be cute and sweet or they can be hot and sexy. The choice of your model, accessories, poses, lighting and other factors affect where your shoot will fall on that spectrum.

This model was working on building her portfolio. She is fifteen an so we did not want to overly sexualize the images. Cute and sweet and pretty was the goal here. Here the sun was setting low in the sky. I worked with Hannah to help her be aware of how the sunlight would create light and shadow across her abdomen if she was turned just right. I used the blue parasol to compliment the sky and her bikini. The parasol also takes some attention away from her body, and gives a distracting element that makes a whole picture, rather than having all the focus be on her body.
With Hannah kneeling in the water, leaned back slightly, shoulders square, it stretched out her tummy to make it look as slim and fit as possible. I used fill flash to soften the shadows on her face and torso. But the sun did most of the lighting. This is a whole body shot, so it does not focus on body parts. I think that helps soften what could otherwise be a too sexy image for a 15 year old.

Here is another full body shot. I’ve included a beach ball prop. I had Hannah jump with the ball. This created a sense of energy and gives the viewer more to look at than just the body. The story here is about the girls energy and joy, not the body. I used sunlight and fill flash on camera for this photo.

Charolett is working hard to build a modeling career. She had never done a swimsuit set and did not want to do a bikini, but did want to try swimsuit modeling. Here in Utah many people want modest swimsuit and designers are going to need models for modest swimwear.
I photographed Charolett with a cloudy sky and a small amount of fill flash. Her body is in near profile, but not quite, her head turned softly, with the chin down slightly, toward the camera. This pose gives a soft, gentle, feminine feel. The sepia takes the flesh tones out of the picture and makes the whole image, with the rough horse coral behind her, feel a little moody. We let the wind blow her hair to complete the feel of the photo.
My next post will be part 2 of a 3 part series and will deal with swimsuit photography that is scenic, or moody, and not body centric.