First make your tesserae -in our case cubes of local stone and tile that were roughly 13mm square when viewed from above. For our room we made 140,000 of five colours, white, red, yellow, blue and dark blue. Then scribe your design in outline on the floor to make sure it fits and to give a guide for each part. Next work from the outside creating a trough, whose edges are formed by previously completed parts or wooden slats of the same height. Fill the trough to the required depth with lime mortar and lay your mosaic (obeying the 7 secret cardinal rules of Roman mosaicists), knock flat to required height with a wooden board and fill in the cracks with a slip of wet mortar that is worked in with a brush. Allow to semi dry then wipe off with a sponge. Stand back and admire. Use of tea/coffee/cake and biscuits is advisable during the process. Use the hammer and hardie to make the odd shape bits that may be required (top left in this training video. After spending 1 day a week laying tesserae for 3 years, find something else to do.