Along the same lines as the "power points" suggestions, this is how I'd like to structure martial characters:
Any character can perform a normal weapon attack for free. Likewise, any character can perform a simple combat maneuver, like Push or Trip,
instead of a weapon attack, for free.
However, if you want to combine a damaging attack with a combat maneuver, this costs you an extra burst of effort - call it an adrenaline surge as a placeholder - of which characters can only do so many per combat.
Characters have a number of adrenaline surges equal to 1 + their Constitution bonus, and once they expend them, they can recover them at the end of a short or extended rest.
Any character has access to this system, but martial characters, especially fighters, gain access to a wider range of options, through themes, feats and class features. These options include:
- Additional adrenaline surges per combat.
- Additional options for gaining or recovering adrenaline surges.
- A wider range of combat maneuvers, including specialised maneuvers related to particular weapons or fighting styles.
- More powerful combat maneuvers (such as area attacks) which expend two adrenaline surges to activate.
- The ability to chain multiple combat maneuvers together on a single attack.
This system puts a limit on spamming of more powerful attacks, but also avoids some of the unrealism of 4e's AEDU system, where a character forgets how to do a particular special move the moment he performs it.