Think about the ice you'll need for your slushy machine

Slushies must get their ice from somewhere, and slush machines will either produce their own ice using a water source or grind up a block of ice that you provide.

I recommend: Most commercial ice slush machines make their own ice, and are actually just ice machines with a function for shaving or flaking the ice. Some companies with an online selection will even allow you to narrow your search of ice machines by type of ice (cubed, crushed, flaked) that you need. Other companies, such as Real Hawaiian Ice, offer machines that either use cubed ice or an ice block that the machine freezes itself from water.

Know how big your slush machine can be

Ice slush machines come in a wide range of sizes--most of the commercial machines referenced above are extremely large freezer-sized machines, but you also can get smaller options for a restaurant or home.

I recommend: For a smaller slush machine, try a manufacturer that offers beverage dispensers that will simply mix the flaked ice and the syrup and then dispense. These don't make or shave the ice, but will mix the beverages and offer a convenient and attractive way to serve them.  Smaller, cheaper slushy machines are available for home use.

Find a deal on what goes in the slushy maker

After you've found a slushy machine you like, you'll need the ingredients to make an ice slush and what you're going to put the slushy in after you make it.

I recommend: Plenty of online vendors such as The WEBstaurant Store sell syrup for slushies and allow you to search by flavor and purchase in multiple-gallon containers. Some manufacturers, including Real Hawaiian Ice, offer handy packages for start-up use of slush machines that include the machine, cups, syrup and other items.

Rent a frozen drink machine if you don't want to buy

If you need a slushy maker for a short-term event or aren't ready to buy one, plenty of options are available to rent you a frozen drink machine and the materials to go with it.

I recommend: Margarita machines are a common choice for frozen drink machine rentals, but you can use them for any type of alcoholic or non-alcoholic frozen beverage. You also can search PartyPOP for renters of slush machines near you. Some sellers occasionally have refurbished slush makers available if you just don't want to commit to an expensive new machine but are still interested in owning.