This line conversion technique works great for most situations. But what if you have an irregular shape, like the end of the house which is drawn in perspective, and you want the halftone lines to follow the lines of that perspective. Here's what I do.

1. Create the halftone lines and place in position as in step 6.
2. With the halftone lines layer selected choose, Edit/Transform/Distort.
3. Move the corners or edges until the lines match the perspective. When they are where you want them press return to apply the transformation. Press Command/period (or the Escape key) to cancel the transform, leaving the pixels unchanged.
4. Use the Unsharp Mask filter to sharpen the lines on that layer if needed.
5. After distorting the lines, the halftone lines will probably not fit around the edges of the shape as before. Just use your favorite editing tools to clean it up. I like to use a graphics pen with the pencil tool.


TIP:
Sometimes it helps to reduce the transparency of the layer, before selecting transform and making adjustments, so you can see what's happening under the layer. You can return it to 100 percent after the adjustments are made.