Pose mirroring wrong Blender newbie here. I have a problem mirroring poses that's giving me a headache.
When I mirror, for example, the left leg, the right leg isn't
correctly mirrored; it's rotated for some reason.

I've read possible solutions and watched some videos,
but I still get bad results.

This is what I do:
First, I create the bones I need:



I placed the 3D cursor at (0, 0, 0).
I select all of them except the torso and head bones. I key Shift + D, then Esc, then Ctrl + M, then X, and finally Enter
to create a mirrored copy. Afterwards, I key W to open the Edit Mode Specials Menu and select to Flip Names.



Once that is done, I go to Pose Mode and move some bones on the right side:



Then, with those bones selected, I press Ctrl + C, then Ctrl + Shift + V to paste mirrored,
but this is what happens:



What could I be doing wrong?
I solved my problem.
For every bone in Edit Mode, I had to set the Roll value to 0.
Then, for some bones with Bone Constraints, I had to set the Pole Angle to 0 or 180.
Finally, I had to clear parents for my meshes and parent them to the bones again.