yeah, basically if you see something that could be considered 'odd' in your real life, you have to automatically ask yourself if you're dreaming.
For example, a clock not showing the right time. You ask yourself if you're dreaming. No, because you're awake.
This could transfer into your dream, and you'd see a clock with the wrong time. Again, you ask yourself if you're dreaming. And you find that you are. Which means that you become lucid.
If you do reality checks frequently during the day, you will eventually do them in your dreams.
I hope that helps.