Too little give a coarse texture and heavy, compact ice cream. Better ice creams are often sold by weight, and federal standards suggest a minimum weight of 4.5 lb. per gallon. Milkfat improves flavor and interferes with ice crystal formation, giving finer crystals. More milkfat will give better body and smoother texture. Also stabilizes the dispersion of air in the foam.
Eggs give emulsifying.
Sweeteners -give flavor. Lowers freezing point of liquid ice cream mixture. Flavoring ingredients -fruit, nuts, cookies, chocolate, candy bars, extracts. Crush fruit before adding so there won't be any large pieces of frozen fruit in ice cream. There are several types of commercial frozen desserts and they all depend on the amount of milkfat in the mixture.