Mike, I could be wrong, but I suspect the OP means an outline of each paw area (of the mold), not a shaded, pencil-like rendition.
If I'm correct, by far, the best (fastest, most accurate, most easily adjustable) way to get the outline would be to use the pen tool to create a path around each impressed area, then stroke that path with some color (eg, red), and put it on a suitable background.
Unfortunately, many people are not familiar with the pen tool, so another approach is to use one or more of the selection tools to select each impressed area, then use the selection / modify / border tool to select a few pixel wide path round each impressed area, and then fill that with your color of choice. I illustrated this method.
1. First, I used the quick select tool followed by "refine edges" to get this selection of the impressed areas.
2. Next, I converted the selection of each area to a border selection a few px wide around each area, and filled that border with red (on it's own layer).
3. Finally, I put a black background under the red border layer.
As you can see, the resulting outlines are lumpy and irregular. This is one of the reasons I strongly suggest the pen tool - it's outlines can be smoothed, stylized, etc. However, in a pinch, the above approach using only conventional selection tools isn't too bad.
HTH,
Tom
PS - Hopefully, my interpretation of the OP's request was correct, and he really did want outlines, not a pencil-like line drawing.
PPS - Given sad nature of the OP's request, please consider this a freebie - I intentionally didn't watermark this.