Fully lining a crochet/knitted hat

Have you ever wanted to add a lining to your hat to make it just a bit warmer?  I had someone ask me for a lined hat and so I was forced to get the wheels turning to put together something that would work and not be terribly difficult.  This process took me about 30 minutes to get together and get stitched in. 

First, make your hat.  I went up a size to allow for the additional fabric, but I probably didn't have to.  As long as the hat is not tight already and the fabric you are adding isn't super thick, you should be ok.

Next, you are going to fold your hat into quarters.  Grab a sheet of paper and trace the basic outline of the folded hat - disregarding earflaps and other additions.  If you plan on doing a few more hats in this size, mark it to use again.
My hat had earflaps, so I traced out just the earflap portion separately being sure to leave a little extra on the straight side.  I probably could have included the shape in my cut out, but this seemed easier.

Now cut your pieces.  You need four of the head pieces and two of the earflaps

Now it is time to sew!  Pick up two of your hat pieces and lay them like sides together.  Sew up one curved side only!  Do this again for the other two pieces.  Lay the two halves like sides together and sew up both curved sides.  You should have a basic hat shape at this point.  If you have earflaps, center the flap on a seam and sew to the main hat piece.

Now from this point you have options.  What I did, was roll a finished edge on my sewing machine.  BUT if you are a skilled stitcher, you may be able to sew into the hat while making a finished edge.  So after I finished the edge, I inserted the lining into the hat.  Make sure the pretty side is out!  I then grabbed a thread that would match my hat and sewed the lining in by hand.  My fabric was fuzzy enough that I made small stitches and it disappeared.

So once you get back to the beginning, you are FINISHED!