How do I create hand drawn looking shapes?

I was thinking that the grid was hand drawn and scanned, but zooming in to 400% reveals an almost certainly digital art look.

I have to go out in a moment, and the grid I made is overlapping and it shows when stroked, so I think I'd do the horizontal and vertical components with different paths. Stroke on different layers, and set to Darken so the overlap was cancelled.  Or maybe leave as it is and double up with Multiply, and reduce layer opacity.  My gut is that the look would be averaged out and spoiled though.  I'll try again when I get home.

The straight lines, arcs, and shapes in the posted example generally look quite precise and machine-made; what look hand-drawn are the textures within the lines and shapes. If that’s what you’re after, you can stay in Photoshop and get a lot done by studying layer blending modes and clipping masks.

In the demo below, the Triangle 1 shape layer remains an editable vector shape layer, it’s given texture by applying a grayscale photo layer of a textured wall as a clipping mask, and it’s given color by also applying a Hue/Saturation adjustment layer as a clipping mask. The clipping masks restrict those upper layers to the shape, and everything remains adjustable. I think many of the effects in the posted example can be achieved this way.

I would draw the shapes and line and afterward use filters…

 But for such hand drawn effects, Illustrator is way more effective

@jeljohnssp why cant you stroke them with a pencil brush?

Perhaps you are using the wrong brushes - check out Kyle Webster's brush packs - they are more organic and simulate media better than the default PS brushes:

https://www.adobe.com/products/photoshop/brushes.html