To Prime or not to Prime?

I want to chat about primers. What are they? How do you use them? Or are primers another gimmick/product designed by cosmetic houses for you to add to your purchase?
Primers are made with a unique formula that keeps foundation ‘budge proof’ and provides long lasting hold of makeup while enhancing the skin’s texture. A primer should hydrate, soften and supply radiance to the epidermis. So in a nut shell, your primer will fill in pores, fine lines and mask imperfections.
A primer creates a thin film which is normally frosted. The best way I can describe this, think of your bathroom window. You can see through the frosted window, you can see that there is a tree/house/dog outside though not perfectly. This is the effect a primer will have. Your primer will dim pigmentation and imperfections.
So when you’re looking for a primer, you’re looking for a texture that matches a lotion. The product should leave a soft and velvety finish on the skin. Light and no oil. Steer clear from primers that contain or feel oily. An oily primer is best suited for a very dry skin type. If you have oily skin, you’ll end up shining by lunch time.
So where do you find the best primers? I have two that I keep in my kit and both have a green tone. Now I am throwing a spanner in the works! Just remember this:
Green – Redness
Purple – Yellow or sallow undertone
Peach – tanned complexion
Red – darker skin types, will brighten the complexion
White – Asian or if you want a porcelain look
Clear/Frosted – Great beginner primer
My top primers:
Smashbox Photo Finish Foundation Primer. I am an addict, I only use the green one. I use it on everyone! You use the size of a pea, not too much! Smooth over the nose, cheeks and chin using fingers. It has a velvety texture. 5/5

Makeup Forever HD Primer #0. I prefer the clear one. Soft lotion feel and smooth over the face using a foundation brush or fingers. Normal to dry skin. 4/5

Makeup Forever Stop Shining +
This primer is ideal for oily skin types. The primer contains Magnesium Oxide, the Mg will absorb oil and keep you shine free without drying you out. Legendary product, I often apply just to my nose in the summer months when I tend to shin. 5/5