So I poked around the Tutorial section of the boards, and came across this:
Paints: - Cheap And Easy Detailing Tricks
A lot of the tool related stuff I already have, but I've noticed this particular post is 10 years old, so I'm wondering if there are more cost-effective solutions that have popped up within the 10 years of this post's existence. I work in a discount store, so things like cotton swabs I can get really cheap, but generally the pens are a bit more difficult.

The ones I'm struggling to find cost effective replacements for are:
Uchida Marvy "Decocolor" Paint Pens
Roseart Colorsharp Metallics (Do these even still exist? Surely if they did, I'd be able to find them on Amazon >.>)

I'd also like to see the picture examples on this thread, since for some reason they are not visible. Does anyone know where I can see them? If not, has anyone got any good examples of having successful colour applications with the normal sharpies? I've found from experience that they tend to have a weird layering effect that doesn't really work to simulate paint application.