Yarn covered letters.

In preparation for a little craft I'm planning on doing as a present for someone, I've been looking at lovely pictures of yarn covered letters.

These are some of my favourites:

An unusual way of displaying initials from Let Birds Fly.

Image from here.

I really liked the choice of colours in this pile of letters, as well as the addition of the flower.

Image from here.

This cheeky addition to this cosy grey letter made me smile:

Image from here.

Covering letters in wool/yarn looks so simple, but I have a feeling that it may be a little harder than it looks. Any tips for making it easier?

I'll post a picture of my finished object when it's done - won't be until next week though as I don't fancy taking both children to Hobbycraft by myself!