In 4-3 the lizards might take a couple shots, but this is fine. Just get as close as you can without scaring them (wear the Thief Ring!), take the shot with your best bow (Sticky Long Compound +5 and heavy arrows are best), and then turn and run away. (I usually hide behind the large monolith). Wait a few seconds and the lizard will come walking back. Repeat until it is dead, and then do the other one.
I have killed those two lizards every time using this method (save for one time when I forgot to put the Thief Ring back on), and ended up with 7 pure Darkmoonstones across New Game and New Game+.
Important things to remember about the crystal lizards: - Always wear the Thief Ring when hunting lizards! - They do not react to arrows that do not hit them. So you can kill anything that is next to one without fear. - If you alert one by hitting it with an arrow from distance then just turn and run away. In almost all cases the lizard will come walking back. (The only exception I have seen to this is the lizard at the beginning of 2-1. I also am not sure about the first 1-2 or lone 3-3 lizards, since I always chase them down.) - In non-boss stages you can load your profile after killing a lizard and you will trigger the next spawn of the lizard if any are remaining. This is convenient for the 1-3 lizard, especially since the enemies don't respawn when you load your profile. Just be sure to collect what the lizard drops before loading!
Anyone can shoot a gun. But can you steer a bullet? Rage Racer. Real. Fast. - Rage Racer ad slogan
Also, I don't know why I never see people say it, but Cloak stacks with Thief's Ring. It is one of the cheapest spells in the game and nobody ever says anything about it. It doesn't double it, but it adds 50% stealth. I have used it hundreds of time with the ring and I can safely say it does make a difference. You can be having something charge you and cast that spell and all of a sudden it acts like you disappeared...lol