You could use the diving trick to get more pwps. Basically, you completely empty your pockets and drop all your money. You then use a wet suit and swim to the furthest corner of the map. Keep your 3ds on, and just stay idle for around 5 minutes. After, just run around and you should get a ping. It may take a few tries though! Also remember that you can only get one pwp suggestion a day! Good luck ^^