So I won a local tourney with the new Eldar Codex, and won these beautiful wraithguard. With all the options they came with, I couldn't just glue 'em together, so I started figuring out how to magnetize them. I used 1/8" x 1/32" magnets from kj magnetics. This shot has most of the important stuff in it. The right arm you can see, has a magnet that I have trimmed to match the size of his wrist. The magnet was just larger than his wrist, as you can see on his left arm. I didn't drill into the arm, just glued the magnet right in top of the wrist. After I started taking pics, I realized that his left sword arm doesn't need the magnet. Just glue the left sword arm to the sword. Or magnetize it for different poses, you don't have any other weapon to put in the left melee arm.
The other impotant thing on this photo is the small finishing nails i used for his hand. You can see a full nail next to a nail that I have trimmed ready to insert into a drilled out wrist. Use a nice, new, sharp micro drill bit, and drill by hand. A dremel will destroy the hand in no time.
Below you can see the wraithguard with a D scythe. I just decided to put the head vanes and hip guards on with glue. I like the look of them, and did't want to go crazy magnetizing every option.