Set goals and go about pursuing them. It requires discipline but once you surpass the initial blocks it becomes second nature. Also, don't forget of yourself. Do some form of physical activity and set some goals for that too. Rinse and repeat.
Regarding goals, I've personally found them to be counterproductive unless they're simply achieved and a matter of habit. For instance, "go to the gym and do nothing" became "go to the gym and walk on the treadmill" when I became habituated to showing up at the gym. Now I'm lifting regularly and I feel off if I don't get a chance to go work out.
Audacious goals, on the other hand, are demotivating because there's too much chance of failure. If I hold myself to lifting certain weights, I may even end up getting injured. But now I'm happy simply showing up, doing what I have the capacity for, whether it's walking, stretching, or lifting. I can (and will) come back if I have an off day.
Scott Adams talks about something similar in Goals vs Systems[1]. A goal of writing a book is much harder to achieve than a goal of typing a little bit in the morning. Ironically, the latter may be the best route to the former...as long as you don't think about it too much :)
