how to brush your teeth
I went to the dentist with bleeding gums, and saw a poster which explained how to brush teeth properly. My gums have been getting better ever since.
It took me until I was 33 to learn this, so maybe it can help other people!
When brushing the front and back of my teeth, I used to hold the brush straight facing my teeth, then circle it around. But the right way is to hold the brush at an angle, maybe 45 degrees, so it doesn't push hard against the gums. Although our teeth do go straight up and down, the gums stick out over the teeth, and if you brush with the brush directly facing the teeth it will hurt your gums. So, hold the brush at an angle, it should push firmly against the tips of the teeth, but not against the roots, and only gently against the gums. Then do the circular brushing motion or however you do it. Be aware of your gums, don't scrub them too hard!
I think that brushing badly, like I was doing, is a major cause of gum disease.
Here are some pages that describe this, many other pages about tooth brushing don't mention holding the brush at an angle.
• http://www.wikihow.com/Brush Your Teeth
• http://www.dentalhealthsite.com/how to correctly brush your teeth