Inverted brick with clip
It would be fantastic to have a 2x2 brick with studs on top and bottom, but LEGO doesn't produce them. But you can! By using a 1x1 clip with studs as the base you can create a brick that is exactly three plates thick and has studs on both sides. It's surprisingly strong, despite only being kept together by a single stud.
The only thing to look out for is to use the correct clip. It comes in two variants: you want the thicker one for this technique.
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.
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