How to use a projector

If you're lucky enough to have a projector, you need to make sure you project onto a surface that's perpendicular to the projector itself. A flat, vertical wall is ideal. You can rest your paper/pad on a shelf attached to the wall (or even screw a baton in for this purpose). You can then use White-Tack to fix the paper to the wall so that it won't move while you trace. 

To change the size of the image you're projecting, move the projector closer to the wall (making it smaller) or further away (making it bigger). Having your projector sit on a trolley, or set of drawers on wheels is ideal for this.