Trade things you don't want with friends, neighbors, relatives. Take your lunch to work. Save and reuse plastic sandwich bags and paper lunch bags. Tie soap remnants in a piece of nylon net and use as a body sponge. Crumpled up used aluminum foil is ideal for scouring pots and pans.
Paper towels are expensive.
Use washable cloth dish towels instead. Wash and reuse transparent plastic wrap. Attend movies early when prices are generally lower. Don't buy expensive gifts. Give exotic home grown plants or bake a cake.