Some people call this their creative muse, some people simply have an end goal in mind. Whatever it is, you need something that keeps you coming back to your easel, something that gets you to explore and brings you through creative dry spells.
Your inspiration can come from many places, music, poetry, faith, love, experiences, nature, or the way light falls across someone reading - whatever it is, it is a reserve that you can tap into to help your art progress forward. Think about what gets you excited, why it gets the creative juices flowing and then nurture it.
For many, producing art is a way to make sense of a emotional state, it could be a therapeutic release from a situation or a way of expressing a thought or theory. Use your inspiration as a tool to guide your viewer and tell them the story you are creating. Your inspiration will allow you to take mark making and infuse it with feeling and liveliness.
One thing I don't recommend is producing art with the end goal of being "rich and famous", which is, in my opinion, one of the most meaningless inspirations in creation. You may get some attention at first, but eventually most people see through the artifice and recognize the lack of raw expression underneath (and if perchance you are one of the few that can become "rich and famous" through this method, kudos to you, I guess.)
Let inspiration guide you, don't be afraid if it takes you in what at first is an ugly or unfamiliar direction - this is where you grow and learn. Just like starting a new type of exercise can be painful at first, if you are diligent about it, eventually your hard work will yield results.
Try new things, attempt to harness and convey that joy in creation, revisit the things that you love in order to become renewed. There is a reason why great artists in history revisit subjects or themes over and over, they are working through something - this gives them energy and a passion that lifts off the canvas and attracts the viewer and allows them in to experience your expression.
Think about your inspiration this week and pursue it - you may find a beautiful new direction.