When I'm building, a couple of things are when I pick a bunch of bricks, maybe like 5 or 6, and then I exit out of the Brick Selector without hitting 'OK'. Or when I do that, and I just go back in, clear, and hit entre. I'm so used to resetting my bricks after I do something, so I do that alot. Also, when I pick the wrong brick, and start to build with it, and then I hammer that brick, and try to pick the right brick. Even then, sometime I dont get the right one.