Spells should more or less be kept as is, but with more powers that inflict conditions.
For martial characters, an idea could be to do the following.
At-will powers should all do 1[w] at level 1-20, and 2[w] at level 21-30.
Encounter powers should all do 2[w] at level 1-12, 3[w] at level 13-22 and 4[w] at level 23-30
Daily powers should all do 3[w] at level 1-8, 4[w] at level 9-18, 5[w] at level 19-28 and 6[w] at level 29-30
A martial character would still get the same number of powers, but their damage depend on your level, not when you get it.
Then, the martial classes should have to buy (feats or otherwise) “special moves” to those powers.
You then have the possibility to add the special move to any power, as long as it is possible. For example, you could buy a special move called: Trip.
Trip: -1[w], target reflex instead. Effect: target is knocked prone
So, if you use trip with an at-will power , you would do 0[w] (you can never have a combination of power and special move that gives a negative [w], and in this case, 0[w] means just stat modifier and other bonuses) and trip the target, knocking it prone. If you use it with a daily at level 22, you would do 4[w] and knock it prone.
Another example:
Improved trip: -3[w], target reflex instead. Effect: target is knocked prone and dazed.
That would mean you wouldn’t be able to do that with at-wills, nor encounter powers at before you are level 13.
Of course, this isn’t balanced, but I am sure the idea is understandable
It would be easy to have all sorts of “special moves” like shift 1 before attack, or push target 1 that do not have a [w] cost, but can just be applied as it fits combat. The more hefty conditional stuff, like stun, dazed, immobilized etc should carry a more significant [w] cost.
It would also be easy to make a power attack “special move”
Power Attack: +1[w] Effect: -3 to hit (for example).
You could even combine those moves, so that if you at level 30 use a daily power to power attack and improved trip, you would get Improved Trip with
Power Attack: 6[w]-3[w]+1[w]= 4[w] Effect: -2 to hit, target reflex and target is knocked prone and dazed.
Obvioulsly you would need to work on some sort of balance...