This is a tutorial/pattern for a crocheted coffee mug cozy! It functions as an insulator and a coaster! The following are the materials needed:

-worsted weight wool yarn
-4.25mm (G) crochet hook
-coffee mug
-tapestry needle

Step 1: Making the Base..

The base is made similar to crocheted amigurumi. It's worked in the round until it's as big as the base of your cup. I had a standard coffee mug and this is how I got the base:

Round 1: Start with 6 sc (single crochet) into a double-ring
Place a stitch marker into your first stitch and move it as you go along, into the new first stitch of each new round. Do not join your rounds!

Round 2: make 2 sc into each stitch (12 sc total)
Round 3: *make 1 sc into the first stitch, 2 sc into the next* around (18 scl)
Round 4: *make 1 sc into each of the first 2 stitches, 2 sc into the next* around (24 sc)
Round 5: *make 1 sc into each of the first 3 stitches, 2 sc into the next* around (30 sc)
Round 6: *make 1 sc into each of the first 4 stitches, 2 sc into the next* around (36 sc)
Round 7: *make 1 sc into each of the first 5 stitches, 2 sc into the next* around (42 sc)
Round 8: 1 sc in each stitch.

You should now have a circle about the size of the base of your cup. If you have a wider cup, do one more increase round before round 8.

Step 2: Making the "rise"..

The next few rounds go up the sides of the cup, hence I call it the "rise."

Round 9 (if you've made a base like mine): After you've crocheted one even round, slip-stitch (slst) into the front loops only of the previous round.

The next round is kind of tricky, as you will be crocheting into the back loops of round 8.
Round 9.5: 1 sc into the back loops of Round 8. Remember, you slst into the front loops ONLY in round 9!

Round 10-11: sc into each stitch.
Row 12 (notice, we're now going to work in rows!): slst into first 3 stitches, herringbone half-double crochet (hhdc) into the remaining 39, ch 1, turn.
Row 13-18: hhdc into each stitch, ch 1, turn.
Row 19: sc into each stitch...

Step 3: Finish It All Up!

After the last row (sc), ch 21, turn.
slst into second ch and each of the rest, back down to the row.

reverse single-crochet down the side of the HHDC rows, across the 3 slst near the base, and up the other side of the HHDC rows. Ch 21 at the top. slst into the second ch and each of the rest, back down to the row. Reverse sc across the top of the cozy and finish with a slst into the bottom of the first ch 21.

weave in all ends with your tapestry needle and you're done!

I made quite a few of these as last-minute Christmas gifts. After the first, you can easily make one in an hour!