As a man in public - going to the grocery store, bank, etc. There are those who wear mid thigh shorts - most who do not wish to give offense (by not showing respect for the cultural norms here) wear those longer short/trousers to at least the knees (if you know what I mean). Tshirts are universal - just don't have obscene words or pictures on them or anything that gives offense to the Islamic religion. I saw one guy in a mall wearing a T shirt that would have got him arrested and jailed in UAE for not being respectful. I don't know if anything happened to him or not.

Be aware if you try to enter some of the drinking establishments dressed as above you will probably be turned away and almost always if you're wearing sandals. It's not a problem for ladies to wear sandals, but the guys can't.

hope that helps