Answer: Set small achieveable goals
Explanation: Setting small achieveable goals is one of the most effective ways to change behaviour.
Like the say goes " Rome was not built in a day. Little drops of water, little grains of sand makes a big mighty ocean and the beautiful city of Rome."
By setting small achieveable goals, they become exponented in the long run. For example, if one has a poor eating habit, instead of just abruptly cutting the diet by 50%, one can start by cutting it by 5% weekly and in less time, the goal will be achieved.