Sorry for the late entry...
I
love the Vallejo surface primer 70.601 grey. It's made for airbrush, but if you get the hang of it, it's really good for applying with a brush. My significant other has serious issues with strong chemical smells which has made me very catious with spray paints. Also, because of logistical reasons I cannot use an airbrush.
There is a bit of a learning curve regarding the application with a brush and what texture you are applying it to. I haven't tried on big flat surfaces though...
It's my go to primer these days. Just wash the miniature first to get rid of solvents and other chemicals. I use a dedicated toothbrush and a mild dishwashing liquid.
If you are into wet blending I can recommend Privateer Press P3 colors.
I'm going to attach a picture of a blood bowl troll. Let's not speak of the loincloth... not happy with it, but the shoulderpad is P3 wet blending. The contrast could have been better, but I can't be picky these days. Otherwise I would never get anything done.
My preferred brands are PP P3 for colours, Army painter for washes but GW for Agrax Earthshade (or whatever it's called these days). The rest is a matter of tricks