Funny my neighbor and I were talking about good and bad classes we have taken last night. Kitty made a great point, make sure you get around to each person to ask them if they are understanding the tasks and make them "feel welcome". She took a week long retreat that the woman (I am not saying who, but you would reccognize her name) showed favorites to her buddies the whole time and hardly even spoke to her! And she was very vauge with her vocal and written instructions.
Perhaps do your (loud and clear) presentation complete and then ask for the ladies to show thier hands if they need to ask a question or be given just a little more help.
I totally agree with giving out a great handout sheet. It makes a big difference is you have to wait a month or two to finish up the project.
I take my recorder with me to some classes. A small video camera to others if I know it is something that is going to take a visual retake for me to remember.
Please do touch on color and scale of fabrics, it does make a big difference in the finished product. If possible use a big layout board in the front of the class. Or poster ... both help.
And last of all, I know your class is going to be great! You asked the right questions ahead of time. Good teacher habit, Roben!