What you need:
Heavy Cream - preferably organic, not Ultra Pasteurized. Don't buy whipping cream, it contains unwanted ingredients. Why not just use Kimball Brook Farm heavy cream.
Large Bowl - preferably metal, very cold
Electric Hand Mixer or Large Whisk Or Blender or Food Processor
Optional - sugar, maple syrup, vanilla, cinnamon, any flavor of choice
If using a bowl and electric mixer or whisk, make sure cream is very cold and the bowl is too. Whip cream with mixer or whisk for 6 to 8 minutes. Just keep at it until soft peaks start to form. Continue until you get the consistency you want. You do not need to add sugar to get the cream to whip. If you would like to flavor the whipped cream, by all means do and add the flavoring to the cream before whipping.
If using a blender or food processor, the time to whipped cream will be much faster. Two or so minutes is usually enough to get to the whipped cream stage, it depends on your machine. Just be careful not to go past the whipped cream stage to butter. But if this should happen, enjoy your sweet cream butter. Even if you added sweetener, sweetened butter is yummy on many foods.