Quick answer
Washing yourself is reflexive: мы́ться, умыва́ться. Washing an object drops the -ся: мыть ру́ки.
Things you buy
The room
What you do
In the morning
Two rooms, not one
In many Russian flats the ва́нная (bath) and the туале́т are separate rooms. Asking for the ва́нная when you need the toilet can be genuinely confusing — ask for the туале́т.
Typical mistakes
Я мо́ю зу́бы.
Я чи́щу зу́бы.
Teeth are cleaned, not washed.
моя́ шампу́нь
мой шампу́нь
шампу́нь ends in -ь but is masculine.
Check yourself
How do you say “I brush my teeth”?