Tiny TwinkleSwaddle Blanket 3-Pack
You can use this every single day, and more than just a blanket or swaddle, this can also be used as a cover for surfaces where you will put your newborn, a bedsheet, a makeshift pillow, a stroller cover, and as a nursing cover. And now that my kids are bigger, we sometimes use this as a hammock or tent for playtime!
I particularly chose this brand because, unlike other brands, this is made of Kaffle fabric, which is amazingly gentle for baby's skin. It is made of 50% cotton and 50% rayon, so it is breathable and lightweight, perfect for our weather!