Seeking Advice on Nail and Skin Biting for my Child

I'd appreciate any guidance or tips on how to help break this habit. Here are a few questions I have:

Have any of your children struggled with nail or skin biting habits? If so, how did you approach this behavior?
What methods or strategies have you found effective in helping your child stop nail biting?
Are there any particular products or tools that you've used that helped discourage nail biting?
Did you notice any underlying causes or triggers for this behavior in your child?
How do you balance addressing the habit without making your child feel self-conscious or stressed about it?

Any advice or personal experiences you can share would be incredibly helpful. Thank you all in advance for your time and support!