Here's a quick tutorial I scribbled out for the ears I made. I didn't start with any patterns, so this is only a rough estimation of the process. There was lots of trial and error involved.
(This is a bit rough, but I might do a better one with pictures if I ever make more ears.)

My ears: https://www.furaffinity.net/view/15935056/
https://www.furaffinity.net/view/16021071/ (I did not make the tail)

Materials:
-stiff backing (I bought some stiff foam-type material with heat activated adhesive on both sides, I'm not sure what it's actually called)
-short faux fur (for the back and inside edge)
-long faux fur (for the trim)
-base fabric (will be inner ear colour as well)
-padded, fabric covered headband (make sure it's sturdy, comfortable, and preferably in a colour matching your hair)
-needle and thread
-fitting pins
-hot glue gun
-scissors
-clothes iron

Step 1:
Cut a rounded sort of triangle out of your stiff backing roughly the size you want your ears. The outer edge should be slightly rounder then the inside edge.

Step 2:
Start to fold and mold the ear around your headband. Start with the outer edge at about the middle of the headband, then gently curve it around the back, with the inner edge of your ear sharply curved around to the front edge to form a canine ear shape. It helps to have photos of your preferred breed for reference. At this point you will want to trim your ear so it makes the right shape.
Once you have one ear trimmed to the desired shape, flip it and use it as a template for the second ear.
**Do not attach your ears to your headband at this point! Keep them as flat shapes!**

Step 3:
(This step is for the adhesive on your stiff foam fabric. If you can't find that, substitute craft foam and hot glue.)
Take your base fabric and lay it over your flat ear shapes. Then take your iron on a low setting and gently run it over the fabric until it is attached to your ears.
Do this on both sides of your ears. After everything is cooled, trim the fabric around your ears.

Step 4:
Place your ears face up on the backside of your short faux fur. Cut out a piece of fur that covers all but about half an inch of the outer edge of the ear. Leave enough space on the inner edge for the fabric to be able to wrap around where the ear is going to be curved. Leave a little bit of space at the bottom that will slightly cover your headband. Cut this piece slightly bigger than you might need so you can trim it later for a good fit.

Step 5:
Once you're happy with the short faux fur, hot glue it to the back of your ear, leaving space for when you add the long fur. Don't hot glue all the way to the edge of the fur, leave a flap that you will be able to tuck the longer fur under. Wrap the longer edge of the fur around to the front side of the ear where it will curve and glue it down. Again, make sure you leave a little bit of fur hanging off the back of the ear.
Repeat with the second ear.

Step 6:
Cut a tall, skinny triangle of your long fur that will be able to wrap around the outer edge of your ear. Make sure the fur is pointing up so that it will form a little tuft at the top of your ear when you fold it over the edge. Try fitting this fur over your ear, trimming and styling until you are happy with the look.
Next tuck the edge of your fur triangle under the short fur on the back of your ear. You may need to trim the long fur a bit to make it fit nice. Glue the long fur to your ear base, but do not glue the short fur to the long fur. It should lay nicely over top. Then fold the long fur over the edge of your ear so it makes a floofy trim. The long fur should cover the outer edge of your ear all the way to the bottom, starting thinner at the top and widening at the bottom. Again, you may need to trim your fur, and maybe even add some patches to get the right coverage. Once your happy with it, hot glue the inner edge of long fur onto the base.
Repeat with the second ear

Step 7:
Now it's time to attach your ears to your headband. Gently curve the back edge of your ear along the back edge of the headband and pin it down. The short fur at the back should hang over the edge a little.
Next sharply curve the inner edge of your ear around to form the same shape you created at the beginning. The front edge of your fold should run along the front edge of the headband. Pin this down. You may need to re-shape and re-pin your ears a few times before you get the shape you want. Be sure you try your ears on to see how they will look.
Now you need to stitch the ear to the fabric of the headband. Start with the front inner corner and go all along the edge of the sharp curve until you hit the back of the headband. You do not need to stitch the back of the ear. Next, put a few stitches in the outer corner of your ear so that it it will hold your structure up in a nice point.
You may want to add a few stitches here and there to hold your ears securely in the shape and position you want.

Step 8:
Lastly, cut a little triangle of long fur and glue it inside the curve of you ear to make a little tuft coming out. This is the finishing touch! Floof and style your ears and they are ready to wear!

If you have questions about this tutorial feel free to comment. :)