Seat belts save lives, which is why the right restraint can mean the difference between life and death in a crash.

Picking the right seat is only part of the equation. Just as important is making sure children are placed in properly or the seat could do more harm than good.

So how do you do that?

The infant carrier snaps into a base and faces the back of your car. Most models safely hold children up to 22 pounds. Newer models hold even more. That's because keeping a baby in a rear-facing seat, for as long as possible, is the safest choice a parent can make.

"The biggest thing we see in toddlers is spinal detachment, where the head seperates from the spine from the crash forces. That's when they're forward-facing too soon," said Susan Saito, a life safety education specialist.

Once children are in the belts, they have to be positioned correctly or they could fly out of the seat on impact.

"A lot of times with these infant carriers, I see parents with this retainer clip all the way down low. I explain that everything compresses in a crash. These separate and [the child] would be moving forward and out of the seat," said Saito.

The retainer clip needs to be at armpit level, no matter what you use.

Convertible seats also have a five-point harness and can be used until your child weighs 40 pounds.

The convertible seats can be used rear facing for infants and front facing for toddlers who are 2 years old.

"The No. 1 misuse with this seat is that parents leave the harnesses too loose," Saito said.

The belts should fit tight over the thighs and shoulders, again, with the retainer clip at armpit level across the chest.

The combination seat gets you even more for your money.

"When the child outgrows the harness [at around 40 pounds], you simply remove the harness and use side guides to guide the shoulder belt and use this as a self-positioning booster," Saito explained.

The final test includes making sure you can't pinch slack at the shoulder.

Some other key points:

1. Always read the manuals and materials that come with your seat.
2. Only use the headrests and inserts that came with your seat.
3. Dress kids in light layers. In a crash, heavy coats compress against your child so put their coat on backwards until you arrive.