You can hire scooter and manoeuver around, cheapest option there ;) if you are solo you can hire scooter taxis called Jo-Jeks and go from place to place. If you travelling in a group then blue bird taxi service is going to be your best option. Note, Jo-Jeks are not available in all areas in Bali and make sure you check your minimum fare while opting for blue bird taxi its mostly 7000 IDR. In my opinion scootering around is best option;)