This is just a compilation of pictures and commentary on my "Greezy Gus's" Model. Not really organized, as a I tend to jump around alot, when I am building. The intent of this is to hopefully share some insight and tips with fellow modelers.

Lots of little external parts to this small building. Step 1 is to make all of the score lines, before cutting the image out.
In this case, the score lines are all to be made on the back side of the image. I typically use a small pin to mark the lines from the front, so I can make precise lines. My preferred method for scoring is to use a dull Xacto blade. Careful you do not go all the way through!
After scoring, I have completely cut out the image from the card, and am now ready to begin folding it into the final shape.
After folding into shape, I sometimes like to use some balsa pieces on the inside, to make it easier to glue all the sides together. As a side note, I also sometimes elect to cut the "glue tabs" completely off.
With the little balsa support pieces in the corners, my opinion is that it helps close the gaps up, as the 2 edges in each corner, have something to adhere to, completely.
This is how I build my windows (doors also,) which are intended to have a "deep inset." I make 2 copies of the inset- the first copy is the entire window, with associated top, bottom and side pieces. I then take the second copy, and instead of folding the brick pieces, I actually cut them out completely, and glue to sticks of square balsa stock. These are then glued to the original piece. It seems to give very nice, realistic, crisp edges, having the card glued to the balsa. The top piece is intended to form an arch, so I either cut it loose, and glue it to the balsa (once the sides pieces are attached,) or I leave it connected to the card, and glue it to the balsa.
Roof piece. Pay attention to the direction that the card folds!
Bottom of the roof. I ended up cutting the tabs you see. In all honesty, I was not sure how to make the tabs work.
This is an example of how I construct a shallow box. In this case, an electrical box, which attaches to the exterior wall. I am all about trying to make the corners nice and tight- with that, I cut 4 little angle pieces, to glue on the inside. More times than not, I cut the tab off, that is visible in the picture, and just the glue the back flap, right to the edge of the sides.
I use this style of tweezers very often- the wide, flat ends, help pinch the sides to the interior angle pieces while the glue is beginning to set up.
Here are a few pictures of how I built the roof blower. I struggled with trying to figure out how to cut out the pieces and assemble them from the file. In the end, I found an empty 35mm film canister and cut it down, to which I wrapped the graphics around, and glued it. This would be the piece that is second from the left. The piece on the far left, was wrapped around a piece of round balsa, that I cut out with a hole saw. A couple balsa disk/ spacers, that were inserted up into the film canister portion, then finally, the bottom piece was wrapped around another round balsa piece.
Here is the main duct assembly, that goes on top of the building. In this case, I left all the tabs on, as there are so many folds, that need to come together. I was actually impressed by the fact that if I cut and scored, as indicated on the image, it turns out very good!
Lots of score lines to make! A little hard to see, but you get the idea. Taking time here, makes the folding not only go easier, but the finished product shows if you took your time.