I had a similar conversation with one of my friends several months ago but I was unable to homebrew this mechanic. Can you please show me an example of a "how a feat should be" ??
It isn't so much about how a feat should be as how combat maneuvers should be, or how classes should be. Basically, if the action or class is
useless without the feat, then all or some of the benefit of the feat should be a baseline part of the action or class.
For example: nobody ever attempts to Disarm a character unless they have the Improved Disarm feat, because you both lose an attack against the target and give the target an attack against you, all while still having the chance of failure. As such, Improved Disarm is not merely
nice to have if you want to disarm someone: it is absolutely
necessary if you ever want to even consider trying without shooting yourself in the foot. So, this is how I think the feat should look like:
Improved Style [General] You fight with your own unique flair.
Benefit: Choose two of the following special attacks: bull rush, disarm, grapple, overrun, sunder, or trip. You gain a +4 bonus on checks made to use these special attacks. That is a +4 to the opposed Strength check to bull rush, a +4 to the opposed attack roll to disarm, a +4 on all Grapple checks regardless of whether you started the grapple, a +4 bonus on your Strength check to knock down your opponent, a +4 bonus on any attack roll made to attack an object held or carried by another character, or a +4 bonus on your Strength check to trip your opponent.
If you choose to improve Overrun, the target may not choose to avoid you. If you choose to improve Trip, when you trip an opponent in melee combat, you immediately get a melee attack against that opponent as if you hadn’t used your attack for the trip attempt.
Special: You may take this feat up to three times. Its effects do not stack. You choose a different pair of special attacks each time.
Note: This feat replaces Improved Bull Rush, Improved Disarm, Improved Grapple, Improved Overrun, Improved Sunder, and Improved Trip. Whether or not you have this feat, attempts to bull rush, disarm, grapple, sunder or trip do not provoke attacks of opportunity.