My go-to bag for any season is Jeni/In Color Order's Lined Drawstring Bag. Daughter dear shared a photo of some of her Christmasy bags in a variety of sizes. Believe me, we've made them all.
I saw Amy/Diary of a Quilter added a pocket to the front of one of her pillowcase pouches. I love her addition of the pocket to hold a label!
Revised to add a link to Wrap it Up! at sew, mama, sew - lots more good gift bag ideas!