It seems to me that if you're going to try to be eco-friendly, then it's probably best to be eco-friendly all the way. Not all of us can do it but this is something that Lottie from Love, Light and Peas has managed really well and so we can take some inspiration from her. Her stationery sets for example are upcycled using materials such as a Private Eye Annual, reclaimed plastic wrapper packaging and recycled solvent-free labels. She even prints her labels using refilled cartridges and she does all of this in a house that is powered by renewable energy!
She also creates knitted and crocheted items, some of which you can custom order.
Here are my favourites from her shop:
Private Eye - Upcycled Stationery/Letter Set
Custom Tags for Craft Fairs