If you have no pressure sensitive graphics tablet and stylus, then it's going to be difficult in Photoshop. Photoshop has a "simulate pressure" option when stroking a path, but it makes the brush thin at both ends and thick in the middle.
You could do it in vector image editing software however, such as Illustrator, since you can apply a brush to a path. It's also possible in Inskcape (which is free - see its pattern along a path functionality). The example below is from Illustrator.
And this one below was made in Inskcape, using the pencil tool, some smoothing, and the brush shape copied from the clipboard in the tool options. I made the "brush" by simply Tracing a bitmap screen capture of the shape from Illustrator. You could do the same by scanning a real brush stroke and Tracing the bitmap. The same is also possible in Illustrator.
The nice thing about using a vector image editor, is that the brush strokes are attached to the path. So, you can edit the paths, and the brush stroke moves with the path like a live effect.