You have to try to grow habits whenever you wake up and before you sleep. For example, you could pinch yourself on daily occasions whenever you wake up or just look at the clock. Just keep doing it, and it'll eventually become a habit.
When you dream, you will subsequently carry out your habit by pinching yourself or something and evidently, something weird is going to happen. When you witness the strange occurrence, you'll immediately acknowledge your dream as a, well, dream and you can start doing whatever you want in your dream from there.
To remember your dream, make sure to wake up from your dream by cutting it short, or forcing yourself to wake up at a sudden interval.