Generally attempt to use tags to aid organization, when possible avoid using words in product descriptions in conditional logic as it is too easy to get false positives or false negatives. i.e.
if description contains “new” will match “renewal”
Either use an automated collection
https://help.shopify.com/en/manual/products/collections/automated-collections
or use shopify flow’s trigger product-added-to-store for the add-product-to-collections action
https://help.shopify.com/en/manual/shopify-flow/reference/triggers/product-added-to-store
https://help.shopify.com/en/manual/shopify-flow/reference/actions/add-product-to-collections