Avoid bad deeds and do more good deeds no matter how small. Do not cease on the path

As the old saying goes:
"Don't assume a good deed is too small to do it and fail to do it.
Don't assume a bad deed is too small to matter and do it"

Another similar quote:

"Although a good deed maybe small, you should make a point of cultivating that deed because grain of sand accumulate over time can grow into a pagoda. Over time you will create a great deal of goodness.

If one does evil deeds, even trivial ones, they can also accumulate from from few to many and can become great evil. In such a case, one will never succeed in cultivating the way.

Cultivation is nothing more than doing no evil and respectfully performing all good deeds.

If you can avoid doing any evil deeds, your blessing will increase daily. If you can do all good deed, your wisdom will increase daily.

Even though it increases, you still must cultivate to without cease, only then can you have success" ~ Shifu Hsuan Hua