Unlike the hand-cranked ice-cream machines of the past, modern ice cream makers are easy to use, are relatively inexpensive and work quickly, which means you can have a fresh batch of ice cream in as little as 20 minutes once you flip the switch.
The most common ice cream machines for home kitchens are electrically powered. Most contain a canister with sides that are filled with coolant. These machines do not need ice. The coolant is liquid at room temperature, but turns hard and very cold when frozen. Once the frozen canister is locked into the outer shell of the ice cream machine and the dasher is inserted, it is cold enough to freeze the chilled custard or other mixture in a short period of time.
The only downsides to these machines are that you need to plan ahead (the canisters require at least 6 hours in the freezer) and you will not be able to make more than about a quart at one time, enough for 6 to 8 servings. You can keep a canister in the freezer at all times or buy 2 canisters.
Another option is to purchase an ice cream maker attachment for your electric stand mixer.
Some people still prefer the old-fashioned, hand-cranked machines that require you to pack ice chips and rock salt (which prevents the ice from melting too quickly) around the inner canister and then to turn a crank. Once in motion, the crank rotates the canister or the dasher, thus aerating the ice cream inside. These workhorses are capable of churning up to 3 to 4 quarts of ice cream at a time, which is plenty to serve a crowd.
This same old-fashioned style is available in electric models, but they still require chips of ice layered with salt. Ordinary table salt will do, however, as electric machines work more quickly.
If you use a hand-cranked or electric old-fashioned machine, be sure to remove the canister from the ice and salt and wipe it clean before you scoop the ice cream into containers for further freezing. Otherwise, the melting briny ice may seep into the ice cream. Also, after using one of these machines, rinse it well to prevent the salt from corroding any part of it.
Finally, if you have enough counter space, machines with self-contained refrigeration are a good choice. With the push of a button, you can churn and freeze about a quart of ice cream in minutes.