Do not exhale in your glass. This will irritate others and will smudge the glass or the cup. Ibn Abbas reported that the Prophet forbade exhaling in a glass or puffing into it.
Do not drink directly from the jug or the container. Beside being unhygienic behaviour, others may want to drink after you who could be irritated. Abo Huraira narrated that the Prophet forbade drinking directly from the mouth of the sheepskin or the flask.