Crowdfunding is a difficult process that requires commitment and time. Authors who are comfortable with self-promotion and are proactive in securing pledges will find their campaigns are more likely to be successful. A detailed campaign plan will also help a great deal.
Remember that if, as the author, you aren't obviously engaged and enthusiastic about your campaign, it will be very hard to convince anyone else to be, and as a result pledges can be very difficult to achieve.
Crowdfunding is not easy, but it is definitely rewarding.