Step 1 - Warm Up
The warm up period is probably the most important step to any practice session. This is the time you spend at the beginning of each practice session doing simple exercises to get the hands losened up. More importantly, it allows you time to settle into the proper midset for the upcoming practice session. During the warm up period you should be paying attention to the small details of your playing such as your posture, tension in your hands and tone production, just to name a few.
Step 2 - Review your previous practice session
I often tell my students that it is a good idea to keep track of what you work on. This does not have to be a detailed description of every second of every practice session, rather, just a brief reminder to yourself about what you worked on and how you felt about your progress for that day. When you sit down to practice, look back to your notes from the previous session and from there decide what to work on for the day.
Step 3 - Play for fun
Learning to play the guitar should be fun and rewarding. If you are always working on technical and challenging material in your practice sessions, you run the risk of getting burned out and may find yourself puting more time between practice sessions, or worse, you may find yourself giving up altogether. It is always a good idea to save some time at the end of each practice session to play for pure enjoyment. How does the saying go? All work and no play... You get the idea.