best way to cover strong colours with white paint

[Akira181]

I got a wall that's painted in a rather bright red and I need to paint it white.

I bought an expensive brand of white paint that the shop assistant said was good, a couple of rollers, and I'm wondering what's the best way to do it.

Should I go for 2 thick coats or multiple light ones?

 

[Bosswhite]

Get a cheap trade Emulsion apply a couple of blinding coats of that first, then a couple of coats of the Quality Emulsion