Thanks alot for the hints, but I have already read these threads and any other thread regarding Epic Maneuvers, New Maneuvers and the like.
By the way, in order to give you a clearer understanding of my project, I hereby post one of my first concept:
Diamond Mind (Strike)
Level: Swordsage 10,Warblade 10
Prerequisites: 5 Diamond Mind maneuvers
Initiation Action: 1 standard action
Range: Melee attacks
Target: One creature
As a part of this maneuver you take a full-attack action against a single creature. All the attacks against this creature are resolved as touch attacks.
If you hit, you deal normal damage.
My biggest problem about homebrewing new high-level maneuvers is to evaluate when they are balanced for their level, nor too weak, nor too strong.