This is the beginning stages of an acrylic painting featuring 1931 Cadillac on the grounds of Independence Hall in Philadelphia.

The building and the car were rendered in complete detail.

The sky has been painted in using a mix of Cerulean Blue, Brilliant Blue and Titanium White.

A mix of Raw Umber and Titanium White was applied to the ground of the courtyard.

At this stage I'm detailing the car's shadow using a mix of Indanthrene Blue and Raw Umber.

 
Using a #4 fan brush I'm roughing in the large trees in the Independence Hall courtyard. I loaded the brush heavily with Permanent Sap Green and little Raw Umber in the darker areas.

If you visit Independence Hall in summer it would be hard to see the clock tower at this vantage point because the trees are actually much more intrusive.
I'm beginning to work in the building details.

Once the large background areas were complete, a #8 flat and a #1 round brush were the only brushes I used throughout the rest of the painting.
Independence Hall is pretty recognizable at this point. The large slate tiles in the courtyard have been painted. I highlighted the color differences in the slate tiles to add a bit more interest. 
Now the real fun begins - painting the 1931 Cadillac.
At this stage the fenders of the car have been painted. I began with my main color which is a mix of almost equal amounts Cobalt Green and Payne's Gray. The top of the fenders are going to reflect the sky, so there is Cerulean Blue and Titanium White blended in there as well.
You can see that the wire wheels are completed as well. An entire day was spent just on the details of those wire wheels - including the tires.
The body of the car is now painted. A mix of Raw Umber, Davy's Gray, Titanium White and just a smidge of Burnt Sienna was used. Some of the sky (Cerulean Blue) is reflecting into the top of the hood.
Here is a detail shot of my home made straight edge. It started life as an ordinary T-square. Its now just a 24 inch straight edge which has rubber bumpers screwed to each end which keeps the straight edge about 3/4 inch off the surface of the painting. These bumpers were found among my assortment of odds & ends hardware, but I imagine something similar can be found at any hardware store. I just drilled a hole through the center of the bumpers in order to accept a screw. I drilled holes at either end of the straight edge and attached the bumpers.
Here's were the straight edge comes in handy - painting precise straight lines.
More straight lines.
Yet, even more straight lines.
Here is the final product.

The final stage is building the frame. I'm building a floater frame for this painting using 1"x2" molding from Lowes. The inside of the frame will be painted Flat Black and the outside will be stained using Minwax "Early American" stain.