Applying the Thinset
Use the flat side of a notched trowel to apply a layer of thinset to the substrate.
Use the notched side of the trowel to comb the thinset into a uniform depth: do not overbuild the thinset layer.
Many manufacturers recommend small-notched trowels for almost all plumb surfaces. Thin-set manufacturers generally advise that it is not necessary to have a greater thickness of thin-set behind a large tile to create good bond with a flat-backed tile. Apply a uniform coverage to ensure there is complete contact of the thin-set.Consult your dealer or manufacturer for the appropriate trowel size for the job.
Put down only as much adhesive as can be tiled within 10-15 minutes - thinset adhesives dry very quickly.