Sketch a thumbnail of the image you want to make in your mosaic. Shade it using large blocks of color.
Choose an old painting with similar colors to those you selected in the thumbnail drawing.
Use a ruler and cutting mat to measure and cut out mosaic tiles from the painting. A craft knife will give you a nice, straight cut but a pair of scissors works as well.
Arrange the cut-out squares on to a table top or large piece of white paper. Try to arrange them by color.
Sketch your thumbnail drawing onto a full-sized piece of paper. Map out each color section to keep the color blocks organized.
Start laying down mosaic tiles beginning with the main subject of the mosaic. Once your happy with each block's placement glue them down.
Continue laying down blocks until your mosaic is complete.
This tutorial is excerpted with permission from <a href="http://amzn.to/1pH0ztJ">"Paint It: The Art of Acrylics, Oils, Pastels, and Watercolors"</a> by Mari Bolte (Author), D.C. Ice (Illustrator), Robert A Williams (Consultant Editor) and published by Craft It Yourself.