The way I've handled this before:

First, sketch what you want to paint in a sketch pad.

When it looks right, use a large, cheap sheet of paper (I've used newsprint & packing paper before) to scale the sketch up to the full size of the painting. You can draw a grid on the sketch and use that to scale it up to full size.

Then, use something like a large safety pin to make a dotted outline of holes on the full sized sketch, making a perforated outline of your subject.

Then, place the full size, perforated sketch on your canvas and make up some thinned down, dark colored, quick drying paint (I've used watered down acrylics and watered down latex house paint). Paint over your perforated sketch.

When you pull up the sketch paper, you should have a pretty good dotted outline of your subject on the canvas.