Hi Demilich, further to 10 Ball's answer, working on your neatness will swiftly improve the look of your minis without having to learn bundles of new techniques.
Simple example, the tall knight...
That chainmail on his legs, the approach is correct, paint black first then run silver over the top. BUT, you need to make sure you have full coverage with the black first. Most of those lttle holes are still empty so look white. We've all been there, every time you think it's done, you shift the mini under the lamp and there are more holes to fill! Persist and the whole thing looks better in the end.
The "freehand" emblem on his chest. Nice try but it's a bit rough. Simple solution that doesn't involve fiddling with a brush? Get a fine line technical marker pen and outline the emblem in black. Easy peasy
Learning to "read" the mini. What was the sculptors intent with regard to the split trousers, gloves, boots? To my eye they're leather, not metal, so I'm immediately thrown by the coppery paint and silvered boot soles. (I've been painting 30 years and a mate pointed out to me last week that a WIP figure had green cloth sleeves instead of metal arm guards. Sigh, repaint ahoy).
Your improvement is clear to see, the halfling at the end has come out nicely. Stick with it and your painting (and photography) will continue to leap on
Cheers, B.