A mighty gift idea could be a high-quality diaper bag that's designed more like a backpack or messenger bag, which can be both practical and stylish for a new dad. Inside, you could include things like a thermos for coffee on-the-go, hand sanitizer, baby wipes, and maybe even a small photo album or frame with a picture of the new baby. For relaxation, consider adding a gift certificate for a massage or his favorite coffee shop to enjoy some personal time. These thoughtful touches not only celebrate his new role but also provide some comfort during the transition.