No secret method, but this is what I do:
For Elves/Gargoyles:
- Put on 100 LRC suit with 2/6 casting
- Soulstone off necro temporarily (so you have 0)
- Lock necro at 0
- Cast Curse weapon over and over and over
You will fizzle every time thus using 0 mana.
For a Human:
You can do the same thing but you need 40 LMC and high MR on your suit too as you'll suceed in casting curse weapon 50% of the time due to JOAT.
It still takes a while, but this is how I train ss once necro trainint is complete. You can use the same technique with eval int by removing magery, but there you will always suceed in casting reactive armor even with 0 magery and no JOAT. If course you and do this in lich form with a dark wisp too.
Happy training!
-OBSIDIAN_