I agree with everyone else...an electric ice cream maker is very nice. If you just put ice cream custard in the freezer, it will freeze, but you won't get the smooth texture, it will be more of a frozen custard....bigger ice crystals. To make with an electric freezer, many models require ice and salt...but some other models use a frozen charger that you stick in your freezer beforehand. Both make a great tasting ice cream...the salt and ice models generally make larger batches, and is more nostalgic for me, but also is messier, as you need to set it up in your sink for the salt water overflow.
Healthy homemade ice cream: Blender only Freeze peeled, sliced bananas in ziplock bag -- (that's your sweetner); add frozen fruit, such as: strawberries, blueberries -- (that's your flavor); add some Soy "very vanilla" milk 1/2 cup -- (that's your protein and calcium); put in blender, and enjoy immediately. Or put in plastic container for later!!! you'll love it.