Complex sentence: Her first attempts at creating art involved carving shell stone from the Pecos River into elaborate designs, a practice which she began in 1956; eight years later she turned to drawing, using a ballpoint pen on paper or cardboard.
Split into simpler sentences: Her first attempts at creating art involved carving shell stone from the Pecos River into elaborate designs, a practice which she began in 1956. Eight years later she turned to drawing, using a ballpoint pen on paper or cardboard.