Keep seat rear facing as long as possible. It is much safer for a child to face this way. Most seats allow rear facing to 40 pounds. ALWAYS READ YOUR MANUAL BEFORE INSTALLING SEAT!

First and foremost, remove snow suit and/or winter jacket. It is never safe to have a child in a car seat with a puffy jacket. Instead, use a blanket or a thin fleece jacket or sweater.

Place child in car seat

Take all harness parts out from under child.

Take sweater from out of underneath straps (shown on one side here) so that the harness is against the shirt, not the sweater.

Sweater is out .

Do up chest clip.

Do up crotch buckle.

Check tightness if harness. If you can pinch it like this, it needs tightening.

To tighten, pull strap as shown (some models may vary, check your manual).

Re-check harness tightness. You should be able to get one finger under it...

... But not two fingers stacked in top of each other.

Move chest clip up so that the top of it is parallel with the child's arm pits.

If it's cold, you can now close sweater over the child's chest like this