I only drink skim (fat free) milk. I just prefer it. But a lot of my baking calls for whole, and sometimes 1/2&1/2. The only 2 ingredients you need to keep on hand for any recipe (or preference) calling for any type of dairy milk are:
Skim Milk and Heavy Cream
Use the mxing chart below to create whatever else you need. Simply add the quantity on the left of the equation to a 1 Cup measuring glass. Then fill to the 1 Cup mark with skim milk to produce the ingredient on the right of the equation.
1.5t heavy cream= 1% milk1T heavy cream= 2% milk2T heavy cream= whole milk5T 1t heavy cream= half-&-half9T heavy cream= light cream2T half & half= 1% milk3T half & half= 2% milk4T half & half= whole milk
(see the original chart at Epicurious.com)
To make buttermilk, add 1 to 1 1/2 Tablesoons of lemon juice to a 1 Cup measuring glass, then fill to the 1 Cup mark with whole milk. Let this sit a while until it has clabbered and slightly thickened..