Text that reads, not text that decorates
Text on an image has to be readable in one second: strong contrast, large enough, placed over a quiet part of the picture. A price or a promo with weak contrast does nothing for you.
Keep some margin around the text and the subject. Pushed against the edges, a visual looks amateur and crops badly across different screens.
Filter and collage: the mood and the proof
A restrained filter, or a committed black and white, pulls a series of images together and gives you an identity. Do not lean on it: the filter serves the content, it does not replace it.
A collage shows a product from several sides, or a before and after, in a single visual. The buyer understands faster, hesitates less, and you save yourself a post.