Short answer: the best photos are those that prove the work: finished work, details, place, process, scale, before and after if useful, simple portraits and photos that explain how to order or request a quote.
Photos should reassure before decorating
A beautiful but empty photo is not enough. The image must help visitors understand quality, material, size, style, finish and working method.
Prepare files properly
Use clear filenames, WebP when possible, compressed images, descriptive alt text and a small set of strong photos rather than a huge weak gallery.