Say : Bism Allah, Mashaa Allah

Bism Allah means OR = in the name of God (Allah)

we say it before doing any thing . we put (bism Allah) with the beginning of all our actions. Why? with every time saying Bism Allah we hope blessings and supporting from Allah, who has the ultimate power of every thing .
Mashaa Allah means that all our good deeds and good actions become increasing and growing up continously without ending or infinity by the good and ultimate power of Allah.  

  Bism Allah Mashaa Allah

Another purpose is when we say it to people who may envy you or us.

We say it to people who have bad intent and dislike you ....It is preventing the evil power of envy you by good ultimate power of Allah.......

Remember if you say the name of Allah(Bism Allah ) in all our actions we must be sure that there is nothing in the universe can never harm us and Allah,the Almighty stand beside us in all every steps.