I'm a decent builder but I wanna know what to do when building and what NOT to do.

If you want to be able to see bricks when you have a transparent brick see below.

Let's say you have two bricks. Brick one was made before brick two, so if I made brick one transparent you won't see brick two, same with brick one.

How do I fix this?
Well just copy the same brick and then when you make one of the bricks transparent you will see all of the bricks.

Hope this may help you.