Quite a few... Bra straps showing. Wearing a black bra beneath a white shirt. Believe me, it IS see-through no matter what you do. Wearing clothes that really doesn't suit your figure, whether you're small or big, it goes both ways. Come on, honestly, it doesn't matter what your size is, you can look beautiful with the right clothes on. But when you're big, please don't try and fit in those tights. Bad idea. Another things is low-cut tops and dresses that show your breasts struggling to breath. It is really necessary? Less is more ladies. Less is more. What are you trying to prove?
Other etiquette disasters are things like manners. Simple manners. Not being rude and obnoxious. Asking your guests if they're thirsty or hungry. Offering. Saying 'Please', 'Thank you' and 'Excuse me'. It's really not hard, and it's definitely not embarrassing. Why people forget that simple fact is beyond me.
The worst of it all for me... When you see someone happy, married, taken or whatever - leave them the fcuk alone.
What do you think?