on the back (obviously) get the low speed side of the table:
I put the centre point on an airspeed, such as 100kt... (Somethnig even, or at least on a grid line) and i turn the glass so N is against the arrow (provided wind is north after magnetic variation) and i put a pencil mark 11kt's above the centre point. Then i turn it to my track. I move the pencil mark up or down to my TAS line, the centre point is my ground speed, and the number of marks off indicates track error.. for every line is 2° Track error, with this you have to alter heading to the direction that the pencil mark is in.
Pyro