I had a hard time finding these monsters painted online, so I'm posting my finished work. There are a lot of effects and techniques that I DON'T do, because they are hard, I don't know how to do them, and it's time consuming, so there is much better work that can be done on these monsters. This is just how I painted them:
Ice Wyrms. I tried to make the master look like he was infused with the treasure he was guarding, it ended up looking interested, but nothing like an Ice Wyrm. If I painted these again, I would probably paint the master the same as the minion, but keep the red highlights. Also, the skin color is much darker which again makes it look more like a dragon, less like an Ice Wyrm.
Dark Minotaurs. I painted the minion more like what I would consider a sorcerer of death and the master more colorful. Originally the Master had a much more purple cloak, but the "highlights" made it look much more blue. If I painted these again, I'd probably switch the color schemes of the master and minion. Although the master is more colorful, the minion ended up looking more menacing. I have switched to painting the master monsters bases to look like some type of land. In this case, grass and a dirt path.
Shades. If I could blend I would have made the red highlights have more of a glowing effect but a. I don't know how to do that, and b. I wanted to be done. These took around 3-4 hours to paint all of them just as is. I did try painting some "glowing" red eyes in the face hole, but it looked really really stupid. Very cartoony. I ended up just keeping the face hole black and painting the "glow" around the edges. If I had more skills I would definitely do a better job with the highlights, blending the colors better. I didn't paint the base of the master other than black with a matching color highlight to it's scheme, these guys just look so dark and creepy I wanted to keep that theme.
Anyway, that's how I painted these guys, if you're looking for a reference or just better ability of visualizing some thoughts you may or may not have had.