New ideas or at least new points of view will surface during the process. Choose the best sketches and draw them more carefully at a larger scale - about 15 to 20 centimetres high. Now check to see if a photographic reduction to 5 millimetres still renders clear details. Sometimes you may want a circular arrangement of letters. To balance the amount of text with the diameter of the circle, it may be preferable to arrange short texts in two semicircles.
Capitals usually work best, because they create a more pronounced ribbon effect.
Hand Book of Type and Lettering.