In one sentence, describe what the following article is about:

Even old hair dye can affect the results. Don't dye or otherwise process your hair in the weeks leading up to the bleaching. Bleaching your hair will work better and cause less damage if your hair is strong and unprocessed. If your hair is damaged or processed, then you are better off going to a salon. Strengthen your hair in the following ways:  Use a natural shampoo and conditioner. Avoid products containing sulfates, which dry out your hair. Avoid chemical-laden hair sprays, gels, straightening products, and other hair products. Don't apply heat to your hair with a straight iron, blow dryer, or other heating appliance. To bleach your hair with peroxide, you'll need the following materials. Gather them together and set them up on a table in your kitchen or bathroom:  A 3% hydrogen peroxide solution. Any higher than 3% and you risk hair loss when applying. Not fun! A clean, empty spray bottle. You can buy a new one at the drugstore, or use an old one. If you use an old one, wash it out thoroughly. If you're going to store the peroxide, keep it in a dark bottle and away from light. Hair clips. Cotton balls. A towel. Gloves. Aluminum foil, if you plan to do highlights. Shower cap, if you plan to bleach your whole head of hair. On the day you plan to bleach your hair, wash and condition it as normal to make sure the oils and grime caused by natural wear and styling products don't interfere with the peroxide.  Condition well with a good natural conditioner. Bleaching your hair with peroxide can dry it out, and conditioner will protect it during the process. Let your hair air-dry instead of blow drying it. Pat it dry with a towel to keep it from dripping, comb it out gently, and let it dry for about thirty minutes. Hair that is a little wet will take the hydrogen peroxide better.

Summary:
Start with  healthy hair. Gather your supplies. Wash and condition your hair.