Wanna see how I do it?
You'll need a sweater made of natural fiber, wool, angora, merino, alpaca, mohair. If you'd like to trim your monster with facial features, heart etc it's good to have some more fabric, I use other sweaters but if you've only got one for your project you can use felt. It's nice to use good quality felt because it's easier to work with and it holds up well, the craft stuff tends to get pills if it's exposed to friction (aka played with or loved up ). If you need a small amount of good quality felt many suppliers offer sample packs or you can call out to fellow crafters (because this place is full of teh love you know).
Now, felt up your sweater! I put it into a hot water wash with some laundry soap and then into the dryer on hot. Sometimes I wash them more than once to get them really shrunk up good and tight. Take care to remove lint from the washer and dryer, there can be a lot.
Here's my pile of felted sweaters. Cut them apart, detach the arms, cut off all the inside seams, the neck band, buttons etc. You can save pockets to use on the back of monsters or as a mouth on the front piece if it will suit.
You will need to cut out a front and a back so two of the same shape. You can cut out whatever shape you like here but I often let the shape of the pieces inform the design. See?
Now the ears. You can use a piece of felt cut into any shape you like and it can be sewn in just like that or you can fold over one or both edges.
Ear with one folded edge.
If you'd like to use a different sort of fabric here woven (non-stretchy, like for quilting) fabric works too. You will cut out 4 of the same shape, I use the same fabric for the 2 fronts and a contrasting fabric for the back. Pin the ears together, fronts to backs. The right side or outside (that you want showing) of the fabric will be on the inside here. Sew around the ear shape as shown.
Take a sharp pair of scissors and trim the point of the ear being careful not to clip the stitches. This helps make the point pointy when you turn the ear right side out .
Turn the ear right side out and press it with a hot iron if needed to make it nice and flat.
The following shows how to insert the ears and where to sew. If you want to add arms you can do so here as well. They can be sewn from felted sweater fabric or felt or woven fabric like you did with the ears. You can stuff the shapes or not. If you do add stuffing make sure it's not in the way when you sew all the pieces together or your machine may have trouble with such a thick layer.
Remember that the body pieces will be right side in, that means that the fabric that you want to show on the outside will be on the inside for this step.
Sew around the body leaving an opening to turn right side out. You don't want a really big seam allowance here so if your stitching is pretty far from the edge of the fabric you can trim it a little, so that it's about 1/4 inch or a bit more. I recommend using pins to hold everything in place before you sew it together.
Want to add different coloured legs? Same process as the arms. You can add legs and arms and ears or any combination of the three, it's up to you and your imagination.
Now cut out some shapes to use as features, eyes, noses, mouths, teeth, hearts or whatever you'd like.
circles and hearts
Here are three finished monsters. You can see the addition of features and hearts. I sew these on by hand before stuffing the monster bodies so that I can tie off threads inside the body where they won't show but you can do it any way you wish. You can also embroider the features but sometimes stitches get lost in the fuzz of the wool.
You can use polyfil to stuff your monster or if you want to use up all the little scraps left over from the sweater you can clip them all up into tiny little bits and use that. It takes a while but it's really nice and makes a terrific fluffy monster as well as leaving no waste!
Now I'd love to see how you do it!