I found that if I imagine what I want to dream as I lay there with my eyes closed as if I am dreaming it.
Some suggest trying to put an object in your dreams to make you realize it is a dream so you can do what you want. I used to do this but it stopped working. I used if I dont see my feet. See in dreams I never pay attention to my feet and If I would look down in them I would just see the floor below me like I was floating. So I knew I was dreaming. I know it's weird but it worked. Well till I got so used to it that it doesn't work anymore.
Apparently practice is the key. Keeping a dream journal, always trying to remember as much of your dreams as possible and not using the snooze button are supposed to help. Some people have it easier than others but I've read the biggest hurdle is simply learning to recognize you're dreaming while you're dreaming. This is why you're supposed to keep track of your dreams so any recurring ones are easier to recognize.
That's my advice
Some suggest trying to put an object in your dreams to make you realize it is a dream so you can do what you want. I used to do this but it stopped working. I used if I dont see my feet. See in dreams I never pay attention to my feet and If I would look down in them I would just see the floor below me like I was floating. So I knew I was dreaming. I know it's weird but it worked. Well till I got so used to it that it doesn't work anymore.