5. Food processor:

"The one that we recommend you get doesn't have to be the largest model. There are these extra blades that higher-quality models come with -- the slicing and grating blades. You want to make sure that it comes with extra bells and whistles. That will help with making everything from coleslaw to salsa," says Engel.

6. Heavy pots and pans:

"They may be a bit more annoying to clean, but they balance out the heat. You're not burning something in the middle and not cooking something on the sides," says Goldberg.

To start with, Engel says, "Buy something that can go from your stovetop into your oven. That will give you more uses."

Goldberg adds, "Something with high walls, like around Dutch oven, has more of a steaming effect than something with lower walls like a skillet." She recommends considering foods one typically makes and purchase the type of pot or pan from which she could get the most use.

7. Porsche of the blender world:

"If you're going to make a huge purchase, the one thing we'd recommend is a Vitamix. We use that every day for different jobs," says Engel. "It can handle everything from a smoothie in the morning to making your own cashew cheese or blending a soup. Making your own pasta sauces. Even juicing. Whereas a juicer filters out the fiber, the Vitamix keeps the fiber in."

8. Coated/wooden tools for coated pans:

The sisters point out that it is important to match coated or wooden tools with the use of coated pans to avoid scraping the lining of the cookware.

"Coated cookware can be safe if it's heated properly, oil is added, and coated tools are used so the surfaces are not scratched. The problem is that a lot of people are not going to be as careful," Engel says, "So when they scratch it, that's when there are problems. That's why [the cookware] gets a bad rep."