Choose a project and give the student a materials list so they are prepared for the next lesson. You can also prepare a "kit" so everyone is ready with the exact same starting point and materials. If you do make a "kit" be sure to talk about the details, such as preshrinking, fabric grain, fabric choices and pattern choice so they know what they should look for when they go shopping on their own. If your "kit" contains the fabric cut for the project, demonstrate how you cut the fabric so they are capable of cutting their own fabric if they want to make the project on their own.
Always have a print out of the directions for each student or a printout of the directions in each kit. This allows the student to make the project again on their own.
Choose a simple sewing project. There are many free beginner sewing projects to choose from but the ten easiest are the best place to start. The first three projects listed on the ten easiest would be my first suggestion. An Envelope Back Pillow can be used by any age group and a potholder is always a useful item. A Simple Tote Bag is always handy to have on hand.
Allow the students to feel comfortable with finishing a project before moving on to a commercial pattern. The first time sewing a commercial pattern should be an "Easy to sew" type of pattern. This allows the student to learn how to understand and read a pattern before trying to also learn more detailed sewing techniques.