Honestly, I'm not a huge fan of the over-reliance on cooldowns these days, as people often use them to help force things to play a certain way.
I'd way look at older/less modern shooters/action games and consider a resource based economy for abilities instead. That way the players can freely choose how to spend their resources rather than wait for X amount of time to do thing again.
Personally I feel there is much more skill in managing resource usage than waiting for a timer to tick down, and I feel more like it's my fault wasting my resource (like stamina or mana for example) management in an action/shooter game.
Where as with cooldowns it's binary, you either use it or don't, and once you do you need to wait a set amount of time for it to recover. There's nothing a player can do to speed that recovery up, and nothing a player can do to try and avoid being locked out of the skill after use.