My parents have always been dollar store fiends, making several trips a month and buying up tons of merchandise for just a buck per item. As such, I’ve always loved dollar stores.

I use them for creating gift baskets, decorating cheaply for a party and simply finding great deals on items I use a lot. In fact, walking out loaded with $1 products leaves me with a feeling akin to total jubilation, as if I’ve just found an extra $20 in my pocket.

But even I know that dollar stores don’t always offer the cheapest deals or the best quality products, so it’s important to use discretion when shopping there.

If you aren’t sure what to buy—and more importantly what not to buy—in order to make every penny count, here’s a guide for shopping carefully at dollar stores:

What to Buy at Dollar Stores

The rule: It’s OK to buy items where the quality is not as important or is the same as products in other stores.

  • Gift wrap: Wrapping paper, gift bags and tissue paper are all anywhere from 50 to 90 percent off what you’ll find at other stores.

  • Party decorations: For the decorations you’ll use once and throw away, like noise makers, plastic table cloths, party hats and confetti, the dollar store is a great deal.

  • School or office supplies: Unless you’re shopping during the cheap back-to-school season, school and office supplies are generally a steal at dollar stores. Along with basics like pens, pencils, notebooks and folders, dollar stores also have cheap deals on craft supplies. You can find inexpensive construction paper, paint, stickers and more.

  • Greeting cards: If your local dollar store carries cards, you’re in luck—no one will be able to tell the difference between a dollar store greeting card and one you bought for $3 or $4 at Target.

  • Dishes: Cheap dishes are OK, but try to avoid items like knives or cooking utensils that could melt, break or simply not work well.

  • Beauty products: Shampoo, conditioner, deodorant, hair accessories and other beauty products are all generally good deals, though you’ll likely find they’re smaller than what you buy at other stores.

What to Avoid at Dollar Stores

The rule: Avoid buying items where the quality is very important. Dollar stores may not have products that are correctly labeled, and some of the items on their shelves are past the expiration date.

Avoid any medications, batteries or electronics that can could potentially be harmful. You may want to avoid toys as well, since they’re likely to break, which is a big choking hazard for babies and kids.

At Your Discretion

There are some items where you have to decide yourself what you value higher: their quality or their price. Common ones include plastic wrap, sandwich baggies and aluminum foil. If you aren’t concerned with their quality, pick them up here.

Know that a lot of food and other items will be much smaller than what you’ll find at other stores, so what might look like a great deal isn’t necessarily a deal at all. As far as food is concerned, it’s typically fine, but make sure to check the expiration dates. Avoid drinks and sodas—you’ll probably find them for less at the grocery store.

Dollar Store Savings Tips

Now that you have an idea of what to buy and avoid at dollar stores, there are other ways you can save money at these thrifty shops. Here are a few more tips for saving money while dollar store shopping:

  • Make a list: Most importantly, you should make a list of what you need before setting foot in the store. You’ll find a lot of great deals, but sticking to a list will help you avoid purchasing unnecessary items.

  • Give yourself an allowance: If you’re not the kind to stick precisely to a list, or pass up a good deal when you see one, set a budget for your dollar store spending before going in. Tell yourself, “I’m going to limit myself to what’s on my list plus another $10 worth of items.” Once you have 10 other items in your basket, head to the register.

  • Avoid tempting aisles: To get in and out without spending a fortune, avoid aisles that might tempt you into buying items. If you’re there for party decorations, for instance, avoid the candy or hair accessories sections where the cheap gummy bears or bobby pins might magically pop into your basket.