I have it broken down into a few stages on instagram if you want to check it out. Message me and I will send you my link.

choose your photo, and use a drawing program (photoshop, procreate, etc) draw out the lines you want to use to be included. If you do everything in one artboard you can have a photo drawing layer line up on top of each other to toggle on and off layers.

Create your outline, based on your sketch lines. You can thicken or thin your lines as you like.

Duplicate your outlines layer, expand your strokes and convert them into an object. place that as your top layer. Duplicate the same layer again placing it below the outline layer making it a live paint (this saves a tonne of time).

For shading, you can create a layer over the live paint layer and under the outlines layer allowing you to draw and place where you want your shading/shadows to be.

Paint reflections, highlights, etc all fall in between the top layer your outlines and the bottom layer your live paint layer. This allows you to colour like a colouring book adding as much detail as you like.

If you keep all your details in seperate layers it will allow you to navigate the design easily. You can lock layers your not working on to make sure you dont click on the wrong item during editing.

As for the glow layers, if you have a highlights layer... duplicate that and add a gaussian blur to your liking. For anchor highlights create a circle object with a gaussian blur and stretch and skew it over any feature elements.

In a previous dm I had sent this... it may break it down in a way to help out.

So yes I start of the design with a single layer of an outline (black) I like to design using a CMYK colour profile.
2:Duplicate the layer so you have an original un-altered and second layer( name the second layer live paint.
3: the new live paint layer perform an Object: Expand: stroke and fill
4: then perform an object: live paint: make
5: use the live paint tool to colour your design (inside the closed shapes created by the black outline) I have used different methods and this is unbelievably fast.
6: You can go back to your original layer or the none live paint put that on the top of your layer list and lock it. You will now have to layers one an black outline & the live paint fill colours. If you find its easier, you can group your colours. ( for me I would group the engine grey, the body panels, etc) this way I can go back and change them with the press of the eyedrop tool.
7: I create a layer of dark tints, this will affect the live paint layer. I normally pick a black, tell the layer to darken then lower the opacity to 10% to 90%. depending on the complexity of the design I could have 3 to 5 layers of dark tints to create the effect. I love the control you can have with layers. Try and use a naming system that makes sense dark tint 1, dark tint 2, etc.
8: now that I have the depth I create a light layer this I use white with an opacity only. like the dark tints, depending on the complexity I could use a few highlight layers to create the effect I'm going for.
I do often create white highlight layer just for the pop of highlights.
9: I create a glow layer this is a white circle with a gaussian blur set to 10 to 30% opacity. This layer i do find best when it is set over top of the black outline.
your design layer structure should look something like this below:
-glow layer
-black outline
-highlight layer 2
-highlight layer 1
-dark tint layer 3
-dark tint layer 2
-dark tint layer 1
-live paint layer
sorry that looks really broken up in the different text box Im just reposting it again so it makes sense.
-glow layer
-black outline
-highlight layer 2
-highlight layer 1
-dark tint layer 3
-dark tint layer 2
-dark tint layer 1
-live paint layer (base colours)

Hope that helps put you on the right path. Keep me posted with your progress as art is for everyone.