The thing about /me length is not that it has to be long or short to be good, it just has to be filled with things that aren't superfluous. "/me sits" is no better or worse than "/me walks over to the bench and sits down.", give your /me's character and depth. "/me saunters over to the bench and collapses down to sit." gives a more interesting description of your character's movements and tells people things about your character in general and their current situation. why collapse? Maybe they're tired, maybe they rush maybe they're laid back and just fall without a care. This is also kind of links in with my second point which is imply instead of state, show don't tell. If your character is feeling or acts in a certain way, don't bluntly shove it in everyone's face all the time - include in your /me's certain little descriptor's which say what's going on. Develop mannerisms and habits for you character, it gives them some depth and uniqueness that all humans have but isn't overly bold and frustrating special snowflake shit. If you develop mannerisms dependent on mood it allows people who know the charcter well to read their mood without having to say "I'm feeling sad." or being overly blunt and obvious with "/me looks upset." or something.
Most of communication in real life comes down to body language and it can be difficult to incorperate into roleplay without properly thinking it through, but if you do it it can add a world of character and depth to your roleplay.
In real life I don't need my friends to tell me when they're upset or angry, I know how they act and know how to act in response.