... creatively kill liches ???
What is your favourite method to kill a lich apart from buying this oftimes mentioned Scroll of Protection from Undead / Magic, just pull all plugs or simply cheat ???

My favourite method is to haste and retreat all characters, use Polymorph Self on one mage, trigger the lich with him, change into a mustard jelly (100% magic resistant), weather his inevitable Time Stop and then pelt him with the other character´s missile weapons. At first I use 50% magic projectiles and 50% normal ones to find out which class hurts him.
For me with just the use of Haste and Polymorph Self liches are no real problem.

Any comments or other suggestions for innovative lich-killing-techniques ???

Not as creative as you, but I use the Druid spell that summon insect that make 1 damages each turn, have 100% chance of preventng spellcasting and can make the ennemies panic.

I love that spell. I use it against every spellcasters.

Depends on which lich I'm fighting. The one in the City Gate District you go in - fire missile weapons - retreat outside when he starts casting spells - wait until his spellprotection wears out - repeat until he is dead

This tactic generally works (not on Kangaxx though)

I tried all sorts of "fancy" tactics on Kangaxx.
Yoshimo set as many traps as possible. I tried to PickPocket an "extra" Ring of Gaxx, etc.

Jaheira and Nalia would put up all sorts of protections and my fighters would use missile weapons....nothing worked.

Finally, I just quit being fancy and surrounded him with my fighters...
Cerek - Wizard Slayer 15th level.
Valygar
Keldorn
Yoshimo
Jaheira

They just did a straight "Pound Down" on him and killed him in under 3 rounds. He never even got to cast his infamous Time Stop.

I made sure that Cerek struck first, so that any spells would be directed at him. In addition to his Wizard Slayer Magic Resistance, he has a pair of gloves from <font color="lime">Arundors Abode</font> that reflect ANY spell below 6th level back at the caster (does NOT work with Area-of-Effect spells, though). That way, he focuses his attacks on Cerek and "most" of his spells either fizzle or zap him.