Just learning a lot from the forum and wanted to share what I have been taught so far as well - maybe someone can tell me that mine was wrong as well :~)
The steps that I am taught are as follows -
1) Rise on both feet (ball of the feet) - this is the first tick. At this it should feel that the left foot has been restrained by the right foot.
2) Release the left foot to go left as if it were held back and place it toward LOD (almost about 180 degree, maybe a little less) and keep the left heel off of the floor - at this position the hip stays on the right foot and the weight also stays on the right foot
3) Start to swing the hip from the right foot toward the left
4) When the hip reaches on top of the left foot, stretch the hip a little bit more toward the left side, which will start to bring the right foot dragging
5) Place the right foot on top of the left foot (straight - toward 12 o'clock; don't step on your left toe though

), making it almost 90 degree (remember the left foot was almost 180 toward LOD). Right foot is going ball-flat, ball-flat
6) Then the hip gets tucked in - the second tick
7) Follow this until you are satisfied

Well, this is how I was taught to fee the voltas in Samba. It worked for me. I also think that fashion plays a roll in dances, so - it doesn't probably have to 180 LOD, could be less, so long you create a 90 angle between the direction of your right heel and left toe (and left heel and right toe when going right). However, if the right foot points toward more than 1 O'clock, it may not look so good. To me it looks like I have serious foot problem.
Hope this helps; however if anyone wants to give me some professional opinion (other than my teacher of course), please feel free. One of the posts said to trust the teacher - I like that advice a lot. I trust mine - so you should trust yours as well - of course if your teacher is a world champ, or 10 dance champs etc - I don't see why you shouldn't trust your teacher - they didn't get there without knowing how to properly do Voltas in Samba
