Low-poly art mesh creation

Question

I want to know if there is a possibility to "cut" the mesh into single objects (triangles, other polygons) I create using Pen Tool? I followed examples in these two tutorials: Adobe Illustrator & Photoshop tutorial: Create a low-poly portrait and Low Poly Art in Photoshop by RedundantPotato...

However the first one seems like too much effort (as I am still struggling with mastering the Illustrator tools and have a deadline on me) and second one isn't accurate enough.

I came up with the idea to just draw the mesh above the picture I'm working on and add colours individually to the polygons.

However the paths I'm creating aren't split into individual polygons but remain a singular path. Is there a possibility to cut a complex path into smaller objects (polygons)?

For example this one

split into individual polys?

EDIT:

I finally conquered the problem thanks to @joojaa here's my first attempt finished (still needs a lot of polishing and patience):

Answer 1

I suggest following workflow:

1. make a white thin lined stroke and start drawing polygons edges with line tool. Make sure you have smart guides on but no align guides.
2. make a small area of polygon edges.
3. select all and switch to live paint bucket tool
4. hide edge color
5. alt click in middle of polygon to pick color
6. click in polygon to color it
7. Once you have done a area start again by setting edges to contrasting color thin lines block edges then merge to the paint bucket fill and so on.

Why small areas? Otherwise you get the feeling your not going anywhere. Plus it lessens likelihood of mistakes.

Image 1: 10 minute workflow test.

Once you have tested the workflow so it becomes fluid. Start over this way you get much better results.

Answer 2

To color in the individual triangles which seems to be your goal, then you can use the Live Paint Bucket (K)

You can then Expand it to have your individual polygons

Answer 3

It's a lot more effort than people think. You need to create triangles only, perfectly connected one to another, in different sizes - areas with less detail will have fewer and bigger triangles etc.

Use a tool to do this like Low Poly Generator Photoshop extension. It generates the triangle structure based on the image details.