With waking up in the middle of the night, it doesn't have to be to an alarm clock. If you can train yourself to get up after you wake up naturally during the night, that would work as well. At the same time, keep in mind that waking yourself up is only one part of the process and not always necessary, depending on the person.

Take a look at the reality checks tutorial. Getting into the habit of questioning the world around you when you're awake will trickle over into your dreams and you will be more likely to catch some detail(s) that is/are out of place and could trigger lucidity. Ask yourself if what's going on at this point in time makes sense and if it doesn't, it's possible that you're dreaming.

Dream (re-)entry (DEILD) is another possibility and it worked a bit for me even before I knew what lucid dreaming was. Look into that as well.