The last non-price determinant is Related goods . Complements are those goods that go well together. Peanut butter and jelly or ice cream and hot fudge are good examples. Even though the price of the jelly did not change, your demand for jelly decreased. If the price of hotdogs plummets then your demand for hot dog buns will probably increase.
Substitutes are items that can replace each other.
Some of you die hard Coke and Pepsi fans won't agree, but you have to look at it from the general population's point of view. Conversely, if the price of potatoes plummets, you'll be eating much less rice as a side dish. Your demand for the rice will decrease. When drawing the change in demand that a non-price determinant creates, you shift the entire curve to the right or left. A shift to the right indicates an increase in demand and a shift of the curve to the left indicates a loss.