The first trick is to use lemons. Lemons have very good lighting effects, but they can be a little harsh on the cuticles of the hair and can dry it. So a good trick is to mix the juice of a lemon with water. The amount of each will be, a part of lemon juice for three parts of water. After doing this, just put the mixture in a spray bottle and spread it all over your hair. For best results let your hair dry under the sun but if it's cloudy that day or you don't have time you can dry it with a hair dryer and the heat will help the process.
The second one is going to be camomile tea. This remedy is better if you want a more subtle, gradual and soft lighting effect. You just have to make tea out of camomile, let it cool so that you don't burn your scalp, and apply it. I find there's two ways of doing this. The first one will be exactly like we did in the first trick. Just pour the tea in a spray bottle and spread it all over your hair before going in to the sun. But, if you can't be standing in the sun until it is dry I would recommend making a rinse out of this tea after you shampoo and condition your hair in the shower (and not rinsing it off afterwards).
Finally, we have honey. Honey is very nourishing and softening on the hair, and it will act both as a lightener and as a hair mask. The best way to use it is by spreading on to wet hair. Also, for it to make its best performance and lighten your hair as much as it can, you will need some kind of heat. You can either put it on for an hour or so while you take a hot bath, or put it on, dry it with the blow dryer and then putting a plastic bag all over your head to lock the heat in.
Hope these tricks help!!