According to the U.S. Consumer Product Safety Commission, Americans own an average of four pillows each — but how many of those are decorative? If you're lacking a stylish home accent that can change the look and feel of your room entirely, it might be time to grab a few throw pillows.

Throw pillows aren't just for the couch — they can enliven a dining room chair, bedroom window seat and even the floor of your entryway. And best of all, there are so many styles to choose from. From solid-colored pieces to those with patterned prints or embroideries, you might find yourself falling for more than one.

To help you narrow down the options, we've put together some basic guidelines to picking the perfect throw pillows for your space. And because sometimes an image is worth a thousand words, we've used stock images to illustrate our point.

Finding Your Pillow Shape

First things first: You should always choose a pillow that fits your decorating and furnishing goals. Some styles will work better than others in any particular space, and you may find yourself drawn to more than one look — showing just how versatile these simple pieces of decor can be.

There are three basic shapes: square, rectangle and round pillows . Here's what you should know about each one of them before making your decision.

Square pillows are the most common. They're right at home on sofas, beds or chairs — but they can also get creative and hang out on staircases or even layered in floor poufs. Just remember to keep the size in check if you want to stay true to their pillowy roots.

Rectangle pillows add a touch of sophistication to any room . With great options available in sizes large and small, you can fit these pieces into just about any place where square pillows work — from window seats to dining chairs. Rectangular shapes are also great for when your couch or bed needs a little extra support .

Round pillows are super handy if your space lacks a defined shape. They work well in both casual and formal settings — from lounges to bedrooms. If you're going for a more modern aesthetic, opt for a round pillow that has a solid color or smooth texture . If you want something classic, look no further than the patterned options.

Finding Your Pillow Fill Material

When it comes to finding the right pillow fill, there are many factors to consider. For example, you might want to look for something that's machine-washable or dryer safe — because no one likes looking at a lumpy ball of fabric after tossing it in the wash (even if you can put it back in its original shape).

If you've got kids or pets, consider stuffing your pillows with polyester fiberfill . It's both soft and durable — so you know they won't be ruined by anyone getting too cozy. If allergies are a concern, opt for hypoallergenic down-alternative pillow inserts that can be shaped into any size or shape .

The pillow fill is also a great way to ensure that your pillows stay put. Some options will even give you the choice of whether you want the pillow form to be plump or flat, which can come in handy if you're planning on placing them under the back of your head while reading in bed.

Finding Your Pillow Cover Material

The pillow cover will likely be the first thing you see when looking at a particular throw pillow . And as it turns out, there are many styles to choose from. Some will have smooth surfaces that feel great on bare skin — while others may be plumped up with everything from feathers to down .

Not sure what type of cover material to look for? Here are some simple guidelines on how to pick the best pillow covers.

If you want something that's smooth and absorbent, consider cotton . It's also a great choice if you have kids or pets that have accidents from time to time — it can be thrown in the washing machine and will last for years. Breathable and lightweight silk or satin pillow covers are perfect for bedrooms that have a lot of moisture in the air. This way, you won't wake up with a sweaty neck because your pillow cover trapped all of your body heat. If you want something casual and cozy, go with a throw pillow made from velvet — it will look great in casual spaces like lounges and dens. For something more formal, try a knit pillow cover . It's great for those who prefer to read or watch TV with their head propped up by a pillow — it'll keep your neck and shoulders supported.To sum everything up, pillows are usually measured by the square inches it takes up on your couch. A good rule of thumb is to take the length and width measurements of your seat cushion, then multiply them together to find out how many square inches you're working with. Depending on whether or not you want a plump or flat pillow, this will give you an idea of how many pillows you need to make sure things look balanced.