When starting out, a lot of people will place their product directly in the center of an image. This works for certain product images, such as product listings. If you are taking an image that shows your product in an environment (on a bookshelf, bathroom, etc.), you may want to consider the Rule of Thirds to create a more professional and eye-catching product image.
Let's apply it to an image.
The lines show where the thirds fall on the image. Keeping your product along any of these lines is considered correct, but see where the intersections occur (noted by the red circles)? These are considered the most ideal focal points for your image. The eye naturally goes to these spots when looking at a photograph and makes the image more pleasing to the viewer.
We placed the candle directly on one of the 1/3 lines. Due to the candle's height and wanting it to be a more close up image of the candle, we did not set the focus directly onto one of the intersection points. Instead, we made sure to keep the candle centered horizontally in the image and kept the interest by placing it in one-third of the image vertically.