This demonstration of a lighthouse painting features the Hatteras Lighthouse of the cape in North Carolina. I like the distinctive diagonal stripes. This painting is just 8x10" yet you do get the sense of scale of how large the lighthouse is.
When placing a single object in the painting, keep it off centered. Do not make a bull's eye out of it. Notice how mine is just to the left of center. I also kept the clouds and landscape very low in the painting. This helps emphases the height of the lighthouse. Even though clouds could be anywhere in the sky, keeping them low is a compositional device to feature the height of the building. Use this when painting tall buildings, tall trees, or anything or anyone you want to give height to.
Using multiple values in the sky also features the lighthouse. Keep the top of the sky darker and make the values lighter as you head towards the horizon. Since the sky is proportionally very large, you can have a large range of values from dark to light to increase the sense of space.
Do the background first - like setting a table, put the tablecloth on first, then the dishes and then the food.
When painting the lighthouse, block in the black and white first, but do not use black nor white. Save these colors for the shadows and highlights. If you go too dark or too light too soon you have no where else to go. So I used a charcoal grey and an off white for the base colors. Then I added shadows or each side of the column and a highlight just off center on the lighthouse and blended to capture the curvature of the building. Notice how the stripes that have a curved sweep at the sides of the buildings emphases the curve of the building as well.
The small scale of the keeper's cottage at the base of the lighthouse also gives clue to our brains on just how tall the lighthouse is. Keeping the foliage in the landscape indistinct also adds to the scale of the painting. I kept out birds as well, to be in scale they would have to be tiny so they would not add much to the image.
No matter the size of the canvas, you can always capture the scale of the image if you watch your proportions when you paint.