Is it ok to mix different brands of skin care ?

I want to use 3 step and sunblock from Clinique and skin care anti aging+ blackhead treatment from another brand ?
thanks.

whats a better moisturizing cream- for anti-aging? La Mer products or Clinique?

or which other- and when i use moisturizing lotion and sunblock in the mornings- which should i put on first?

Which anti-aging products have undergone scientific scrutiny?

I am 30 and have nice skin, but I'd like to keep it that way. I've been using sunblock for years, but I'm thinking of using anti-aging products as well. However I don't know which products have actually been researched using proper double-blind studies and which products companies are just saying are good.

Do you know which skin products have actual research backing them?