Classification of GRD product


just as your advices ,I had do it on snap with RF to classfy the GRD products,my steps like :GRD-calibrated- GLCM-filtering-Muitilook-Terrain correction-RF(not train the samples),is it right?I wnna to classfy the product to 3 types.if not what should i do?
please reply me ,thanks in advance!