Repeat after me: re-gifting is not a sin. Just don't make the mistake of giving it back to the person that gave it to you.
So you got a perfectly nice gift from your Aunt Mynra, but it's just... not you. You can't return it. What do you do? Throw it away? ACK! Put it in the closet or attic or basement and forget about it? That's pointless. It's OK if you know someone who would just love the scent of that perfume that isn't right on you, or really could use that small appliance, seeing as you already have one of you own, or would go nuts over that sweater that's a little too pink for you... It's a beautiful scarf, but you don't wear scarves. They are precious earrings, but you prefer gold over silver... we have all been giving something that would be... well... better for someone ELSE.
Re-gifting is the ultimate form of re-using. If you can't use that gift, but someone else can, what's the problem? Again, use common sense: were they there when you opened the gift in the first place? Might want to skip it. Is it something unique that might get worn around the person that gave it to you originally? Well... better not. But while you're thinking about shopping, try shopping for a few minutes at home. Say someone gave YOU a spa gift basket, but lavendar makes you sneeze. Make some nice little adjustments, maybe add some other little items, and give that lavendar treat a new home with a better purpose. By all means, GIVE it to someone who will USE it. Otherwise, you're just going to stare at whatever it is for a few years, then get disgusted and throw it away in a fit of Spring Cleaning. 'Tis better to give, much better, than to throw away!
Say it again, out loud, for all to hear: re-gifting is not a sin. Now go shop in your closets.