Realistic planning
To improve the prospect of completing on time, and avoiding procrastination, you need to:
be realistic about when you can/will start;
devote time to planning and revising your plan;
try to work out if any of your research will take a set amount of time to complete;
allocate appropriate time for any travelling you need to do for your research;
include other (non-dissertation related) things that you have to do between now and then;
have clear and achievable objectives for each week;
focus on one thing at a time;
leave time for editing and correcting;
reward yourself when you complete objectives that you have timetabled; and
if you fall behind make sure you spend time reworking your plan.