I had heard of some of these, but others were new to me:
To make food look appetizing in advertisements, food stylists use a bunch of tricks that may not even involve edible objects. For example, syrup on pancakes is motor oil (because it doesn’t absorb), Elmer's glue is cereal milk (it prevent the cereal from sinking), shaving cream is whipped cream (doesn't melt), and dish soap helps the head on a beer appear foamier and last longer...