With two hands (The Elder Scrolls 5: Skyrim)

Press Tab -- equipment - weapon - choose a weapon to paint or PCM
Then Table - magic (you Can get back on f/A or In/D) - the category of magic Type/School- select magic (or cry) PCM or LKM
At the same time to use in each hand the weapons and magic you can cry
You can also add the weapons,gear and magic in the favorites and use the key + Rd/Q
(All keys by default).
I.e. in each hand-arms - 2 might and magic on top of another as in the Witcher is not

ElenaD
All just need to do 3 steps to secure the weapons/magic, SkyUI interface.
- Access to Equipment, assign R (e.g. Sword)
- Open the Magic, assign L (e.g. Flame)
- In Magic to assign to Z (e.g. Unrelenting force)