Hi Musetatron,

You can give a try to following steps:

1) Create straight hierarchy of leg joints
2) Position the hip joint according to your model use the perspective view.
3) Rotate hip joint in any axis to reposition knee and ankle according to the model
4) finalize the hip joint position.
5) For knee joint you can just rotate in ZAxis if your joint orientation is xyz with Positive Y as up-axis
6) Switch the translate mode to local and move knee joint in X-Axis to reposition it.
7) Repeat the same steps for ankle as knee was done.
8) You might have to move or rotate hip again and again based on your knee and ankle position but this way you will never lose the single plane rotation for IK's.
9) Keep looking from different viewports along with perspective.

Hope it might help you. I am sorry if you find difficult to understand this, as I have never posted before. But you can ask me if you have any querry regarding this solution.

Regards,
Vipul Jain