Soi is one of the most often misused French pronouns. 

Soi is the third person indefinite stressed pronoun. It is used only for unspecified persons; i.e., with an indefinite pronoun or impersonal verb. It is the equivalent of one or oneself.


On va chez soi. Everyone is going (to his or her respective) home.
Chacun pour soi. Every man for himself.
Il faut avoir confiance en soi. One should have confidence in onself (in him/herself).
Tout le monde doit le faire soi-même. Everyone has to do it him/herself.

Some French students get confused between soi-même and lui-même. If you remember that soi can only be used for unspecified persons, you should be ok.


Il va le faire lui-même. He's going to do it himself.
On va le faire soi-même.

We/You/They are going to do it our/your/themselves. (See 'on' lesson for more information.)