Plate with hole
LEGO's geometry is not always apparent, but a standard 2x2 area is 5 plates tall. We can use this fact by combining a #2444 and a jumper plate to create a 90 degree stud change.
To find the different pieces needed for this technique you can search LEGO's online Pick-a-Brick for the design ID's. We link other market places directly on each individual piece page, which you can find below.
Videos
Did you know that Swooshable has a YouTube channel? Subscribe to it to see more of my hands and learn cool LEGO techniques.