This is something very easy to make and wont take long to make and can save you one day if you forget your keys. And most people think of it just being under the mat but never check inside?
Step 1: Get a Mat
Step 2: Tools
Get a pair of scissors, plastic bag, item you want to hide (keys)
Step 3: Cut Hole on the Side of the Mat
Make sure you have good scissors to cut it because it is hard to cut