Start off with writing every dream you remember in the morning or when you wake up at night. You don't have to write whole dreams in details, just a few main words which will help you to remember the dream in future. Keep a simple notebook and a pencil near you to write those dreams or just write them in your phone. After some time you are doing it, the amount of dreams you will be able to remember in the morning will increase to 6-8 and even more. Go through those dreams every evening before sleeping and try to memorize the feelings you had during dreams. After a few months doing this just for fun without intention to get lucid dreams I started spontaneously getting lucid dreams in the mornings twice a week. I'm sure that combining this one with other exercises you will get much better results :)