The face is a really fun part of making a felt animal. This is where your critter really starts to come to life as you give it personality with a facial expression.
You are going to take one of your white circles and place it on the face.
Be careful with your ribbon, you don't want to sew through it as you add the face features.
Starting at the back of the face, to hide your knot, stitch your eye in place. I find 4 stitches usually does the trick for the white of the eye. You can use the double running stitch or the back stitch to sew the eye. Do this for both eye whites.
When you sew the eyes make sure they line up. You want them to be approximately the same distance from the edges and at the same height.
Sewing the pupils is just like sewing the whites of the eye! Just repeat the steps. If you are using stiffened felt for your eyes sewing through the layers is a little tough.
Now your monkey has eyes! My monkey is looking up and to the right. Before sewing, experiment with placing the pupils to figure out which direction you want your monkey to look.
Now we're going to add nostrils. Starting from the back you are going to come up through the face.
Making a slightly angled stitch you are going to go through the face to the back of the head.
You are going to repeat the same steps for the other nostril.
When making the nostrils you want to try and have them line up on both sides at the top and bottom. How wide you angle the stitches controls how big the nose will look. If you want thicker nostrils, go over your stitches a second time to make them stand out more.
Making the mouth is a lot like making the nostrils. Start by coming up through the back of the face.
I'm using the double running stitch to make my monkey's mouth but the back stich also works just fine. The placement of your stitches will depend on the mouth expression you want your monkey to have. Mine is going to have a little frown.
I find 3 stitches makes a nice little frown shape. I'm using the double running stitch still, filling in the gap I made with the first pass at the mouth. 
I wanted my mouth a little thicker so I doubled up my stitches. To double up your stitches, just sew over the ones you've already made. Be careful not to put the needle between the threads of your stitches.
Your monkey face is almost done! Now to the most fiddly bit of the pattern...the brow ridge!
You want to place the eyebrow right above the eyes, but mostly overlapping the grey face shape. The very tips of the brow don't overlap the grey shape.
I'm going to sew the brow with the double running stitch. I find starting in the middle for small fiddly bits works best for me. We are going to start at the back of the head again to hide our knot.
As you sew the brow you'll be going through the brow shape, the grey face shape, and the gold head shape.
I find about 4 stitches works nicely to secure this shape.
You'll want about a 1/4 inch on each end without a stitch. Once you've got your brow shape secured you monkey's face is finished!
Next we'll be talking about sewing the feet and giving your monkey toes.
The Golden Lion Tamarin pattern is available for purchase here.