Lavarmos - proofreading please
Lavarmos nuestro las manos antes de comer.
We wash our hands before we eat.
Thank you
2 Answers
Lavamos nuestros manos antes de comer.
Scratch that, it seems the more common (/correct) used phrase would be Pumpkin's "Nos lavamos las manos antes de comer."
As a bonus, "Lávate las manos" (informal), "Lávese las manos" (formal), would be the way to tell someone to wash their hands. I figured that would soon come up in the situation. 
I would say:
Nos lavamos las manos antes de comer.
Reasons: Lavarse is what's called a reflexive verb. This means that is addition to conjugating the "Lavar" part (think of "lavarse" as "lava + se") into the correct form (in this case "nosotros"-- "lavamos"), you have to find the right reflexive pronoun, in this case "nos"; "us". In most cases, we put the reflexive pronouns before the verb when the verb is conjugated, except when the verb is an affirmative command (telling someone what to do: "di", "diga", "hagan", "sea", "haz") or a gerund (like in English "-ing" ex: "comiendo", "caminando", "siendo", "viviendo", etc.) or an infinitive (such as "lavar", "bañar", "comer", "ir", "ser", etc.).
You also do not need the word "nuestro", because in Spanish you generally use the definite articles ("el", "la", "los" and, as in this case "las"--they all mean "the"), when referring to body parts (such as hands in this case).
These are some helpful links to help you figure out reflexive verbs like "lavarse". They can be a bit tricky, but once you get used to them they get much easier, like everything.
SpanishDict Video Lesson 2.5 Reflexive Verbs
SpanishDict Grammar Reflexive Verbs and Pronouns
Study Spanish Reflexive Verbs 1
