The first step in self development, then, is to concentrate single-mindedly on Paradise. Indeed, the one who is unsure of his destiny in life, torn between this world and the Next, like one standing with his feet in two separate boats - will be thrown off balance. Many of the difficulties that we face are due to this lack of commitment and inability to focus on the real and ultimate goal. If you can keep your focus on Janna, then everything else will be possible.
The selection of the ultimate goal of Paradise must be made consciously and may involve an absolute break with the past. To choose this new goal as the ultimate goal in one's life is in fact to choose a new life, to begin a new journey. Embark on this new journey by refreshing your wudu (ablution) and offering two rakas (units) of Salat or Prayer reminding yourself of all the punishment of Hellfire you have just resolved to avoid at all costs and all the rewards of Paradise that you will strive to achieve. Remind yourself also of the important stations and landmarks on the journey; imagine death as near; imagine the moment when the Angel of Death will declare, `your time is over, now you must follow me'; imagine that moment when you will be made to stand in the presence of Allah, Most High, so that the final judgment of life may be passed on you and imagine the consequences of that judgment. When you have completed the two rakas then resolve once more that all efforts will be directed towards achieving Paradise, beseech Allah and pray with humility:
O Allah, I ask for Your mercy and whatever brings me closer to it, in word and deed.
O Allah, I ask for a faith that will never vanish, a blessing that will never diminish, a pleasure that will never abate, and the most elevated position in Paradise distinguished by the companionship of Your Messenger, Muhammad.
While improvement in your habits and actions is a life-long process, the desire to achieve it can thus be sparked in a moment. This desire will provide the momentum for attaining your goal - the good pleasure of Allah and Paradise.
Please go through the whole book It is very inspiring.