How does one accumulate blessings? It is from a number of actions, not just one. There is a saying, ‘Don’t skip doing a good deed just because it is small, and don’t do a bad deed just because you think it is insignificant…’ For example, you should not think that a little lie is of no major importance. If you tell a lot of little lies, they become a big lie. In the same way, you should not think that killing an ant is a small and unimportant matter, because if one day you kill a person, it will have begun with your killing the ant.
You should pay attention to little things and not follow your whims and wishes. To cultivate diligently the accumulation of blessings involves being very careful to do the deeds that should be done, even if they accumulate only a small amount of merit and virtue. Gradually they cause an accumulation of great merit and virtue. Mount Tai [a mountain in China] is made up of individual motes of dust, but even though motes of dust are small, many of them gathered together make up a mountain. So too is the creating of blessings.
Source : thedailyenlightenment.com