Here are a few examples of using photo references:
https://www.deviantart.com/phelandavion/art/Inspiring-STOCK-Example-XXII-455884378
https://www.deviantart.com/phelandavion/art/Inspiring-STOCK-Example-XXXVII-499092787
https://www.deviantart.com/phelandavion/art/Inspiring-STOCK-Example-VI-441051591
https://www.deviantart.com/phelandavion/art/Inspiring-STOCK-Example-VIII-441651606