Basics
Basic Position - Unless otherwise stated this is the position you should always start with. Your feet should be no more than hip width apart. Your feet should be facing forward and should be parallel to each other. Your knees should be slightly bent and never straight or locked. Your pelvis should be tucked comfortably under you but not so far that the pelvis is tipped forward.
Basic Kneeling Position - Unless otherwise stated this is the position you should always start with for kneeling floorwork. You should be on your knees with your hips over your ankles. Your hips should be slightly lifted so that when you move you rear will brush against your heels.
Always...
1) Remember to breathe.
2) Keep your muscles relaxed (don't tense up)
3) Smile :)
4) Have fun with it
Never...
1) Do something that hurts.
2) Dance if your not having fun
3) Let yourself get frustrated with it (this stuff takes time and practice).
4) Completely lock your knees (anytime I say straighten within descriptions it does NOT mean fully to a locked position. It means you return the to a soft neutral position from which you started in)
When doing figure eights...
try to keep the movement parallel to the floor (when doing horizontal) or the wall(when doing vertical).
Middle Eastern Dance is based on only a couple moves...
Which are put together in numerous combinations using layering. For example a hip circle with a 3/4 shimmy in a circle is done first by doing a small hip circle then adding on the 3/4 shimmy and finally walking around yourself in a circle. It's all a matter of layering the moves on top of each other. So learn all the basics first and then it won't take you long to learn some of the more complicated combinations. Break those combinations down to the basics and then layer them back on till you get the feel for it.
Go with the flow...
If you make a mistake just go with it, make it look like you meant to do it. Never stop because you made a mistake or forgot, at least keep dancing an improvised version. Work your mistakes into the dance. Sometimes you end up doing something you like better.
Respect the Dance...
There's a lot more to this dance than learning the movements so do your best to learn the movements in context and expand on your knowledge of the cultural aspects of this dance. Please do not give into stereotypes or proliferate them to the general public. Like any skill that you want to improve you must practice and you must continue your education in it and further developing yourself and the dance.