Hi @Love2shop ,
That’s a great question.
To provide the best guidance possible, let me better understand the situation. Do you intentionally allow overselling out-of-stock products, and in what scenario?
If not, you can always untick this option for any existing products. That way, a customer won’t be able to order sold out products in the first place. But when that happens, you can offer a related product of interest to them and capture that sale using an app called Alternative, Related Products.
Most Shopify themes allow you to enable ‘order notes’ so you can collect extra details from customers for each order they place. Here’s a page on Shopify’s help docs with more details.
If you’re comfortable editing code, here’s a forum link for a tutorial on adding cart attributes to your store’s theme. This is an advanced tutorial, and knowledge of HTML, CSS, JavaScript, and Liquid is required. Consider hiring a Shopify Expert if you aren’t comfortable doing the steps in the tutorial.
Finally, you can check out some apps on the App Store that have a built-in feature for cart attributes. Find the complete list of available apps here.
I hope this helps!