A couple things I have learned the hard way: LABEL everything, especially cords and pedals. Bring an Ott light as lighting isn't always the best. Use a small notion called a wood iron (think glorified Popsicle stick) for pressing seams. Often there are real irons available to share. Bring a coffee mug for whatever you like to drink....those styrofoam cups are yucky! If you are bringing your own projects and not making a mystery quilt, precut all your fabrics. I always do this and then I can just sew and not waste time waiting to use a cutting area. Also, I find it prevents measuring and cutting mistakes that can easily be made when you are distracted talking with friends. Bring some non-messy snacks to share, and some baby wipes for quick clean ups. Lastly, don't forget to bring some oil and cotton swabs to take care of your machine when you are doing hours of sewing. Have fun!