Reuse boxes.
I can not tell you how many boxes I had in my oversized bathtub (Day 14 post) that I was saving to use for presents this last Christmas! Every time I received a box in the mail, it went into the tub. I started shopping early this year, so there were a lot of boxes in there!
I have known people to save boxes in their garage for a long time in case they need them later, but I don’t recommend that as they can take up a lot of space unless you break them down. They can also bring roaches as they love to use boxes for breeding grounds. (Yuck!) So, I would say if you know you aren’t going to return an item, then find the box another home, be it the recycle bin or something else.
I have seen lots of people advertise their left-over boxes as moving boxes and sell them to others for much cheaper than they could purchase new ones. I think that is a great idea.
Kids love big boxes (we are using one right now as a cave,) so you could check with nearby daycares to see if they have a need for one.
Last year I saved all our shoe boxes to use for Operation Christmas Child. It was really fun filling the boxes, and it felt great to give something special to a couple children in another part of the world. If you have not heard of this program, you should check out the link above. They do a lot of great work.
In this generation of online shopping, there will be no shortage of boxes. Before you recycle your next empty box, ask yourself if there is something else you could do with it. If all else fails, put it in the recycle bin.