I sometimes use a medium of some sort, but I always only use them when I have a particular need for that particular medium. If you always, as a rule, add a complete cocktail of media to your paint, then you have simply made things awkward for yourself. Instead of learning how to handle your paints with only water you've learned how to handle your paints with a lot of stuff in them and that has become your normal state. It is better to learn the basics using only water and then use media if/when you have a need for a particular effect. You may even, like Skel, come to the conclusion you NEVER need any.
