Search console was returning a lot of soft 404 errors

Hi Guys, I recently started helping a friend with his ecommerce site (women`s shoes). There are hundreds of products being sold, and as you`d expect some of these sell out from time to time. Search console notified me that it was returning a lot of soft 404 errors. I sent these on to the developer to assign correct 404`s to these pages. I am wondering is there anything else I could be doing as regards to best practice? Should I be looking to de-index these pages once the product is sold out? etc? As you can imagine this will probably happen quite regularly, with style and seasonal changes etc. I`m new to the ecommerce environment, so would like some advice on what is the best path to take. Thanks in advance. :)