The Pick Up achievement is NOT from picking up literal items in the level but from walking over the little blue orbs that can be found throughout a level. There are 3 in each level and for some you will have to be a specific height to reach them. This guide is less about HOW to get the orbs are more about where the orbs are located as there are many ways one could easily REACH the orbs.
1) Underneath the dining room table. Just move one of the chairs, crouch, and you will see the orb up against the bottom of the table top. Just stand under it and stand to grab the orb
2) Open the cabinet under the sink. It doesn't look like there is anything under there but there is a blue orb located directly behind the drain pipe for the sink. Crouch down and move the right way and you WILL see it. You need to be quite small to get this one.
3) The TV stand has two cabinets on it. Open the left cabinet and crouch to see this orb. You have to be about half height or so to get this one.