Sometimes people are motivated more by moving away from something they do not like, other people get motivated by think about moving toward something they love. This is the fundamentals from Freud's Pain/Please Principle, if you can figure which way you are motivated the majority of the time you can adjust your strategies. For instance people for who are motivated by moving toward pleasure having a board with pictures of your goals such as a house you want to buy, ext..
Other people who get motivated by moving away from pain my want to see their mortgage payment like @davemerry said. Everybody is different, however one thing that I have done is notice what is motivating me now versus what motivated me when I started my websites. For instance when I started I may have wanted to buy a car, but if I bought the car or just do not care about cars anymore then why am I building my sites(a question I ask myself)? Perhaps now my personality has changed and I am more of the moving away from pain type, looking at a mortgage bill may get me moving.
There is a very good book called Emotional Intelligence by Daniel Goleman. Another great book is Think and Grow Rich by Napolean Hill which you can download the EBook for free. BTW I am not a DR/PHD, I just have a backround in psychology