Usually, I prefer to get stuff in camera (even if it means light painting my subject). But sometimes Lighting or space limitations will make getting the picture in-camera hard or simply not worth the effort. When such situation strikes go for a composite. If you only have little gear, this technique will also help you get a more professional look in your images.
The actual shooting depends on how many lights you got and how many layers in Photoshop you are willing to use for the final image; it can take a minimum of 3 images up to 20 or more depending on how you light the product. I prefer moving my lights in different angles just to see the outcome and choose the best option after.
The general idea is to place the camera on a tripod and make sure your product is in a static position – if either the camera of the subject move, this will not work. You can use different techniques for lighting your product but for this shoot, I just used one speedlight with a small softbox combined with an acrylic sheet for the gradient reflections.
Step 1: Select the photos that you want. Each photo should have at least one highlight that you are happy with.
(There are different kinds of techniques to doing this but I do mine this way)
Step 5: Select the first layer and add a Layer Mask.
Select your brush and set the color to black. Brush on the parts that you want in your photo.
After that, select the layer mask and press CMD+ i to invert the mask.
Step 6: Repeat step 5 on the other layers until you get the final image
Wanna try this? show us your results in the comments