Until about 3 – 4 year age kids can’t really draw or fill, but is important to practice a FreeHand Painting which can help them to get practice.
It’s very important to practice this techniques on really large sheets of papers which can bring freedom.
But vital alternative can be a large enough 3d objects like stone or clay based flowerpot.
For this kind of paint we use an Tempera (poster paint) colors. !!!! Use only non-toxic ones designed to be used by kids. !!!
There is many Tempera like colors available, but really ideal is to use washable ones, which can be removed from kids closes up to 1 hour from application.
But anyway I recommend to get for your kid a special painting closes with plastic over the for this activities.
PS: On pictures you can see one really needed instrument – paper towels 
See more Tips & Tricks in my Daddy’s Corner
