Tipping is your way of showing your satisfaction and gratification. So there is no hard and fast rules as to how much you need to pay. But do keep in mind that most employees are paid very less and they depend on "tips" to run their families.
This is what we paid.....
Bell Boys/Porters : 1JD
Restaurants: They charge 10% service tax but still you can give them/waiters the change(if you are happy with the service)...that's what we did
Glass Bottom Boat : We paid the charge they demand/ask. So we didn't pay him anything extra.
Tour Guide: We paid 5JD to our tour guide in Petra.You can pay according to his service.
Horse Cart: The driver didn't ask anything extra and so we didn't pay him.We paid him the charge he demanded.You may need the service of horse cart in Petra
Horse Ride: Though we paid him(the horse boy) the amount he asked/demanded still while paying him he was asking for tips. So we paid him 3JD extra. He demanded 7JD as his service and 3JD as tips.
Driver: During our 5days stay in Jordan we had the same driver. From welcoming us to Jordan at the airport to dropping us back, Nedal was with us.He was clear to specify that he is not a guide, but his insight and contribution in making the trip enjoyable and interesting turned out to be even better than having a guide.Nedal was full of interesting information including the history of the places we saw, knew all the best places to stop and went out of his way to make sure we saw the real Jordan. We think he did a good job. We was a perfect gentleman.So we paid him 100JD for 5days(20 JD for each day).I feel we paid him really good because most travelers pay between 5-10JD each day.Read in two-three websites suggesting to pay 2-3JD per day. We really felt very bad that during Eid he was with us leaving his wife and 3beautiful kids at home.He would get lot of calls from them and said it was nothing unnatural because his job demands 24x7 duty.But they are paid really less with only around 400JD per month as he informed us.