Do not break dishes that are made of glass. These will shatter and create many dangerous shards, which could result in painful cuts. If the plate has an interesting pattern, try to preserve it by hitting the plate around its edges. Another option is to put a piece of self-adhesive paper over the pattern before breaking the plate. This will keep the pieces together so that they can be used together in a mosaic.
Mosaic patterns are available.
Just trace the pattern onto the surface where the mosaic will be applied. Use tile adhesive to stick the mosaic pieces to a surface. Grout comes in many delightful colors. Use a plastic spatula to spread the grout, and even it out with a wet sponge. Wipe off excess grout with a dry cloth.