According to the ritual described in
The chapter on discipline in the Bodhisattva Stages,
Take the vow from a good
And well-qualified spiritual teacher.
Understand that a good spiritual teacher
Is one skilled in the vow ceremony,
Who lives by the vow and has
The confidence and compassion to bestow it.
Normally the bodhisattva vow is taken in front of a teacher, although if no teacher can be found, it can be taken alone. The teacher must also have taken the vow and understand how to perform the ceremony. Ideally they should have a wise and loving nature.