Usually this consists of setting Active point limits, Defense Limits, Damage Limits, Attribute Maximums and Combat to Hit/Defend Values (OCV/DCV) in all the various variations, as well as limits on how many points you can get from disadvantages etc.
Most GMs use this, the prescribed system. Ultimately players take these not as Maximums but required. So that inevitably everything is bought at the maximum at start to survive.
Which means that everything pretty much stays the same and nothing goes beyond X and there is little variation, except in tricks to get around opponent defenses etc.
Boring, and well, Unrealistic.
I'm thinking that one solution mechanically is to remove the top Active Limit on abilities, and instead limit in an interesting way. So that for say every 25 points of Active Power you put into a power you must take a 1/4 disadvantage on the power. You can put as many points as you want but you will have a growing compounding of cost down the line in when you can use it and how it will work.
Thus a 25 point power must have a single 1/4 limit, a 50 point power must have 1/2 in limits etc.
You want a super high powered attack? Sure, you just need to limit it, by say making it take longer to set up/prepare, or depend on a foci that can be broken, or which takes a lot more Endurance energy than a low power version, or which you need to spend more effort and concentration on (and thus make you vulnerable to attack as you can't dodge while preparing it) etc.
Then you can build the character that has a Pistol and the Guy who has the Shoulder fired anti tank weapon and you know the guy with the Pistol can quick draw and shoot it in a single round while the guy with the rocket launcher has to powerup, acquire target and fire a whole lot of pain at someone and that the rocket launcher guy might get shot while he's doing his thing. This makes the smaller fast combatant valuable in some situations that the rocket launcher isn't. Which is a bit more realistic than both of them doing the same amount of damage potential in the end (which currently happens in hero builds).
It forces players to be creative, and for more variation in designs of various abilities.
Am I making sense?