I think it depends on what kind of class you are taking. Will you be learning something new or just working on your own project.s For sure take basic sewing supplies (BSS) thread, seam ripper, rotary cutter, bobbins, scissors, cutting mat, rulers, extra needles, fabric, leader-enders, cushion for sitting in case chairs are hard, your own pillow if you are spending the night, and snacks. Sometimes I take little gifts for the others at the retreat like seam rippers, scissors minders or some other little thing to remind them of that fun time together. Anyone else have suggestions?