The Best Hair Thickening Cream in my opinion is the Dove Styling Cream and Hair Thickening Cream.
Walmart Stores sell the Dove Styling Cream and Hair Thickening Cream for around $6.00 and I've had great results with thickening my hair when using it.
Some other good hair thickening products are Oribe Maximista Thickening Spray, Tresemmé 24-Hour Body Amplifying Mousse, R+Co Rodeo Star Thickening Style Foam, O&M Atonic Spritz.
Some of those are sprays and not creams but they are good products for hair thickening and hair styling.
You can also thicken your hair using coconut oil and coconut oil helps improve your hair color and shine and helps add moisture to your hair too.
I do a hot oil hair treatment with coconut oil every few months and it keeps my hair shiny, moisturized and healthy and makes it stay thick.