When you're fighting a fish — especially with light line — the 'experts' tell you your drag should slip freely and smoothly, allowing the fish to take line as it wants.
Bullhockey! Who does that leave in control? The fish? Hey... that's a great idea. Let the fish control the outcome. Except I'll bet he'd prefer a different outcome than you would. Wait... maybe it leaves control of the situation in the hands of the engineer who designed the drag. But I don't know him, and I certainly don't trust his judgement. He's not on the water with me. He doesn't see that log the fish is headed toward. Truth be known, he probably doesn't give a flyng hoot whether I ever land that fish or not.
I'll tell you who I want in control of the situation... ...Me.
Toward that end, I never rely on the built in drag on my reel to do anything more than absorb the shock of my trademark 'powersnap' hook set, and even then, only with light line. First of all, drag is a misnomer. It's a slip clutch. By definition, a drag would add resistance, making it more difficult for the fish to strip line. The way the slip-clutch-they-want-to-call-a-drag really works, is by limiting the amount of resistance the fish must pull against in order to strip line.
With spinning gear, fishing with a tight drag, and with the anti-reverse off, I allow a fish to take line when I feel it's necessary, by back reeling. Back reeling is not just 'reeling backwards'. It's a system that involves reeling in whichever direction, at whatever speed is necessary, to maintain a fairly constant load on the road. At the instant the hookset motion is complete, your rod should be fully loaded. From then on, you want to keep about 3/4 of that same load on the rod.
To do that, establish a 'base position' with the rod handle pointed at more or less a right angle to the direction of the line, and your arms extended just enough to be comfortable and to allow you to move the rod to direct the fish. Once you've established that 'base position', use a combination of extending/pulling back your arms, and reeling in whichever direction is necessary at any moment in the fight, to maintain that 3/4 load or bend in the rod. If you just concentrate on maintaining that bend, the rod will tire the fish, and the fish will be moving toward you whenever it's not pulling away.
It's a bit more difficult with casting gear. For some reason, I've never felt comfortable actually reeling backwards with casting gear, even with the few reels that allow you to turn off the anti-reverse. Instead, I keep my left thumb at the ready, to hit the freespool button and to maintain tension on the spool when I must allow the fish to pull line. Keeping the thumb ON the spool as you're working the fish, allows you to back the spool up a hair with your thumb in the same motion that you click the thumbar, which makes disengaging the spool at the instant you need it, a lot easier.