Here is my first attempt at some conversions: Captains of Numenor. Nothing real elaborate, I wanted to keep it fairly simple so just did a head/hand swap.
This is just an extra Isildur model that I removed the head and added one from a spare warrior of Numenor and changed the direction his head is facing. Other than his heavier armor than the standard warrior, I added the yellow trim to his robe/surcoat to help distinguish him since he is still wearing the standard infantry helm. I thought about adding a shield to his left arm, but decided that it might not look that great.
This shows the first captain with my second to his left. He is just a spearman who I added a sword hand. There isn't much to distinguish him from the other warriors other than his different pose, so if I try another conversion I have in mind, he may go back to being just another warrior.
Job well done. 