If you haven't seen it, this video can help speed up the process: Skins - Spine User Guide: Skin Workflow

The PhotoshopToSpine script can help sorting skins if you're starting a new project, because you can already put the right elements in the slots.

spine-scripts/photoshop at master · EsotericSoftware/spine-scripts

Hi, would it be possible if I already made an animation and would later change the art?

I was animating a quick animation sample for a job interview and I also do the artwork puppet but only a quick digipaint cutout of a warewolf. I completed 2 animations( idle and walk) then my boss approved the animation and now is telling me to detail the artwork now before it will be completely approved.
Is it possible to replace my art with new detailed art with retaining my overall animations and mesh deformations? Thank you in advance.

If you manage to just do an overpaint on the meshes without changing their dimensions then you could reexport everything painlessly. But you must lock your layers' transparency or the meshes will get distorted. Good luck with your new job!

Thank you so much. It worked painlessly I tried to quick test it and turned my art puppet to grayscale and spine just automatically replaced it while retaining all my animations ^ ^.

One thing though,, i was planning to add some extra effects and expression to it like for the eyes to have squint, close , and glow.

My new question is should i just add some layers with different eye expressions in the photoshop file and export it again or there is some other way to do it. Won't it negatively affect my current animation?

Thank you in advance.

Adding new layers shouldn't be a problem, I usually keep the mouth separate from the eyes even on 2.5D rigs, and I'd suggest you do so in order to have different possible combinations. you can create them in Photoshop and then export them as usual. Since the new images weren't present when you made the rig, you'll have to import them as a new skeleton and then drag them into the old skeleton, while the older ones will just get automatically updated.
Your old animations won't be affected if you follow this method, the only thing you'll have to do is tweak the new images if you turn them into meshes, which is a usual thing.

Hi,I'm very sorry for the late reply. I really appreciate your quick help and fast reply.

I've added additional layers and replaced the character's art design with more details without a problem. Here's some animation that I did.

I also would love to hear your advice and critiques in my animation. As you can see I'm quite new to this job because I mostly focus on Illustrating and concept art. Now I'm devoting my time learning animation and becoming expert in the field thus I'll really appreciate your helpful advice on this one. Thank you very much in advance.