One thing that has helped me is to save that cup of morning coffee until after work. This may not be advisable if it prevents you from being able to sleep at night.
Also, treat your study time just like an appointment. Don't answer the phone or allow yourself to get distracted. Train yourself to get right to work and not dilly-dally around.
With that, set weekly goals that you want to accomplish. I use my white board in my office and set weekly goals of what I want to accomplish. I do this for everything and it helps me keep my life organized and on task. Another great tool is a simple spead sheet that has your entire week blocked off like a calendar by hour. Go through and fill in each day with your current activites. Chances are you have more time than you think throughout the week to study.
A final note, see the GMAT as a way to begin forming solid study habits that you will need for school. Use this time to get into the habit now. If you're going to B-School full time your day will be filed with classes, course work and other activities. So, it isn't going to get any easier. Get your body into the routine now. You can do this a little at a time by learning how to set goals. Here are some tips I compiled for an article I wrote a few years ago:
Set Both Long- and Short-Term Goals:
Short-term goals help to break a long-term goal into small, achievable steps. A long-term goal might be to improve your verbal score by 5 points, while a short-term goal may be to master a particular type of sentence correction problem you miss on a consistent basis.
Make Goals Challenging but Realistic:
Kyllo and Landers (25) found that moderately difficult goals lead to optimal performance. Goals that are too easy may not inspire and motivate a student. Similarly, a student who is attempting to attain a goal that is too difficult may become frustrated and eventually give up.
Make Goals Specific & Measurable:
Specific, measurable goals are easier to evaluate than vague goals.
Identify Goal Attainment Strategies:
The experts here are good for helping do that.
Set Positive Goals Rather Than Negative Goals:
Negative goals may trigger negative self-talk, which is associated with poor performance (49).
Consequently, it is better for an individual to focus on what they want to achieve and not what they want to avoid.
Put a time Limit on Your Goals
Locke et al.'s (27) definition of a goal implies that goals have a time-limit associated with them. This is because humans have a tendency to procrastinate. Placing a challenging but realistic time limit on a goal will remind an athlete to keep striving towards its fulfillment.
Commit to the Goal-Setting Program
Commitment is a vital factor in goal attainment (47). Uncommitted students may not be prepared to do all that is required to achieve a goal. Making a goal attractive and developing self-confidence can promote commitment,
Good luck!