I don't have any experience but would say that your items would be great pictured on a model outside, surrounded by nature so that it mimics your floral hairpieces.
Your photographer probably already knows that, but that's one thing I can think of. Also, outside photos are great!
Also, you may want the photographer to do some really nice flat lays that are really popular right now. Maybe do them on a linen or burlap background, something natural but that would contrast with your white and silver pieces.