Always make sure you fully prepare before lightening your hair.
A few weeks before lightening, start doing conditioning treatments every 4-5 days. Apply a hair mask or thick conditioner on wet hair and keep it like that for 15-30 minutes. This will give you enough moisture to keep the hair cuticle strong.
Stop washing your hair 3 days before bleaching. The scalp will build up some oil which is an additional protection.
Do a hair strand test and allergy test, by getting one strand and seeing how your hair reacts to the treatment. If it reacts badly, immediately wash off and do not use the product.
The lightening is restricted for recently chemically straightened or permed hair. Allow yourself at least a month after these treatments. Also, do not use the lightening if your scalp is sensitive or irritated.
If you follow these instructions, your hair will be beautifully blonde in no time!