Fill your white sock with rice. You will need a hefty amount, but it's up to you how filled you want your snowman to be.
Once you are happy with the size of your sock snowman, tie the top with the rubber band.
Take another rubber band and place in the middle/upper section of the rice-filled sock to form the head shape.
Glue the buttons to the bottom side by using a glue gun (glue dots work fairly well too). If buttons aren't your thing, you can also use rhinestones or beans.
Draw the mouth and eyes with a black marker or with black paint.
Add a ribbon for the scarf. A glue gun works best for ribbon. You can cut off excess white sock, but you can also wait to tuck it in with the next step.
Cut the colored sock, discarding the heel and ankle section, you just need the mid-foot/toe section. Roll it a bit and place it on the head of your snowman. Leave it as it is, or you can secure it with some glue.