We use a reflexive pronoun as a direct object when the object is the same as the subject of the verb:
I fell over and hurt
myself.
You might cut
yourself.
We can use a reflexive pronoun as direct object with most transitive verbs, but these are the most common:
amuse
blame
cut
dry
enjoy
help
hurt
introduce
kill
prepare
satisfy
teach
We do not use a reflexive pronoun after verbs which describe things people usually do for themselves:
Michael dressed and got ready for the party.
She washed in cold water.
We only use reflexives with these verbs for emphasis:
He dressed
himself in spite of his injuries.
She’s old enough to wash
herself.