Ok, firs step, establish your motivation. Think of it as a mission statement. For me my motivation for work out to establish a healthy lifestyle.
Second step, establish measurable, attainable goals. (Set a goal date also). For example I want to improve upon my triathlon time that I set last year.
Third, plan a path to achieve tour goal. Set smaller milestone goals that will help keep you on the right path.
Let me know what you decide for your motivation, goal and plan.