Hard headband. I picked these up in a five-pack from the Dollar Tree.
Black craft foam sheets. One sheet should be enough to do your ears if you like them about the size I do, but I always pick up an extra just in case.
Pencil and whatever object you want to trace to get your ear shape. This is the third pair of ears I've made using this glass tumbler from my kitchen, so at this point I know it's a size I'm going to like.
For this particular pair of ears, you'll also want some ribbon in the colors of your flowers. Minnie's original crown has a more plummy purple, and a more teal-ish blue, but my flowers work better with these colors, so that's what I bought. I picked these up from Walmart for something like $.39 or $49 per roll.
Flowers! Also a Dollar Tree score. To be honest, I find it easier to make flower crown mouse ears when I use cheaper flowers. They're easier to pull off their stems, and "flatten" a bit more easily too to conform to the headband shape when I need them to. I took a photo of Minnie's headgear to the store so I could match the flowers as best I could.
Also needed, scissors, and a hot glue gun. I also recommend using a Quaker Oats container to actually work on when you're creating your ears. Try not to glue your ears to the container, but even if you do, the paper should tear off and you can clean up later.
(Side note: These containers also make magnificent Minnie ears storage holders)
Lay your traced object on the craft foam and create a shape similar to this...two circles of identical sizes, connected by a small strip. Cut out the shape including the center strip.
Sandwich the two circles around the headband, hot glue in the center and along the strip. Make sure you know where you want the placement of your ears before you glue them in place. For instance, I prefer smaller ears, and wider placement instead of right on the top of my head (because I have a long face shape, and don't need any more height added)
Place your ears on the container and use your photo reference to start gluing your flowers to the headband and ears. Important note: When at all possible, try to cut off any remaining "stem" on your flowers as you can. This will make your headband more comfortable and keep plastic pieces from jabbing into your head all day when you wear them. Not fun.
For the ribbons, I cut each color to the same length, layered them in the same order on each side, and then hot glued the living daylights out of them. I covered this hot glue mess with more flowers.
And you're done! One great thing about flower crown mouse ears is that if you have any hot glue or rough edges showing, you can add more greenery from your flowers, or a little flower piece, or whatever.
Now to wear them to Disney!