I paint all my models from a grey basecoat, I buy one of those little Tamiya cans.
Best I've found so far, they spray with just a few shakes, and dry in 10 minutes.
One little trick to make your life easier is to organise your paints by color and hue
I have all the paints I need to paint any hue of red, in the order in which I need them.
I just have to pick somewhere to start and keep going brighter, until it's bright enough.
I usually paint with a Shading wash (the darkest hue I want, with A LOT of water) into which I blend my brighter colors.
This shading wash usually contains black, but I've seen people do great things with other shades.
That said, I'm still trying to find out what works on which colors.
With red for example, I've had the best result with layering on loads of invisible layers to gradually build up the color.
Looking at your models, everything (except the back of the eldar's cloak)... They don't grab my attention, there's nothing to make them pop.
The eldar's cloak has a lot of contrast, the rest.... not so much.
Try going a bit brighter for your highlights.
And as a further tip, my personal motto when it comes to painting:
Try everything and find out what works for you.
Hope this was at least of some help

-Mourner