Start by drawing a large rectangle with a smaller rectangle on top of it. These are the two main levels of the castle. Next, to make the many towers of Brightvale Castle, draw four long, vertical rectangles and two shorter, smaller ones. These rectangles should be almost perpendicular (at a right angle) to the first two rectangles you drew.
On each of the four larger tower rectangles, draw four small rectangles that intersect them. For the shorter towers, draw two small rectangles at the top of them. Finally, make a fanlike shape on each of the two top corners of the smaller horizontal rectangle you drew in the first step.
In the very top rectangles that you drew on the towers, make some rounded tower roofs. Then, give the walls' edges a ridged pattern.
Once you've erased your extra lines, give the building some more detail by adding a few lines to the rooftops, more ridges to the tops of the walls, and some decorative lines on the towers.