What changes would not shift the demand curve for a good or service?

The demand curve can shift either to the right or left. A rightward shift increase the quantity demanded at every price level, while a leftward shift decreases the quantity demanded at every price level.

consumer income increases ⇒ rightward shift

number of potential consumers increase ⇒ rightward shift

price of substitutes goods increases ⇒ rightward shift

price of complementary goods decrease ⇒ rightward shift

consumers expect a price increase in the future ⇒ rightward shift