One thing about many adventuring parties is that everyone in it is usually stuck in certain defined roles for the entire existence of the characters. This also means that if a party is lacking someone who specializes or is at least competent in a certain area the party will be severely crippled in that area and then often it would be one person doing all the work. So an interesting exercise I thought we could attempt would be to try and create a party where anyone can become competent in many different areas (given some preparation time).High level prepared casters can often solve any problem with the right spells but the challenge here is to not make the character reliant on spell casting to be versatile. The parties should be about 3-4 characters and should be able to fulfill a variety of roles both in and out of combat effectively. Try to list the functions each character can effectively fill and try to find situations where these characters would be unable to function and how this could be fixed.
Example
Factotum/ Chameleon (skill use,trapfinding, melee combat, ranged combat, healing, battlefield control, buffing, debuffing, blasting, scouting, stealth, social, and item creation)
Binder (as above but without trapfinding)
Warblade/ Warshaper/ Shapeshifter/Master of Many Forms (really good combat versitility, scouting, long distance travel, disguise based social, most of the mundane applications of monsters, warblade combat abilities)