What are some great 'natural' hair products?

I would definitely use olive oil. Also, mayonnaise or vinegar to condition. Lemon juice is fun as well to bring out the gold highlights. I'm a believer in natural products.

Are there products one should never put in their hair?

I don't like to put harsh chemicals in my hair. I read every label because the more natural the product, the better. I don't like a lot of alcohol in my hair and a lot of products have alcohol. I try to use it very minimally.

Should an owner ever trim their dog's hair?

Sure! I trim mine and I'm good! If you have a knack for it, go for it. I love to cut my royal poodle's face, especially around the eyes. It depends on the dog, but it's up to the owner. You can always have the mistakes fixed.