I've been searching high and low how to do this. We have items which are already on sale and we want to create a 20% discount on everything that's in the cart (entire order) except for the items that are already on sale. I hope that makes sense! I've tried doing the tagging method and automated collections method, but all it's done is either added the 20% off on the individual products, or it does take the 20% off the entire cart, but includes the items that already are on sale (giving them a further discount).
Any workaround solutions? App suggestions?
Thank you in advance!