I wouldn't be buying "not my president" stuff until the fat lady sings...March 4th.....because if we believe in what we're told, Trump will be our president....
The idea is to use it against Biden. Most people think he’s the President now.
You don’t have to go out and buy stuff. (I wouldn’t, unless you know you are buying from a like-minded patriot business.)
You can make your own flyers, t-shirts, business card-sized notes to post on bulletin boards, etc.
You can include a pic of Biden to make it clear who it refers to.