Go to Fishmarket South where the Helitour is located to find a big line of people waiting to board a chopper. If you stay in that area where the choppers are, you can beat people up without getting wanted levels. It is rare but you might get a star.
You can also use this location to get easy money by killing everyone standing in line for the helitour at Fishmarket South. Eventually there will be corpses all over the place you will see that the money on the ground will appear again and again. Repeat this until you are satisfied with the money you have collected. Note: The background will start to flash or objects may disappear. Simply leave the location and return and it will return to normal.