The mirror should be right in front of your window so that by looking at the mirror, you are also facing the window. That way, the natural light hits your face.

Buy a dressing table with a mirror attached (even if it's from a charity shop) , place it in front of your window. That way you have all your makeup on the table in front of you, and you have natural light to do your makeup in. I have one in my room and I don't know what I'd do without it!

Just to add to that , if you've more than window in your bedroom, go for the south facing one if poss.

You can buy daylight mirrors from Argos & Boots, which have special daylight lightbulbs around them - they are fab! xxx