First off, keep in mind that if you're going to free-range on a regular basis there's no way around the fact you're going to take losses. Things tend to get really bad with predators later in the winter and early spring. To date the majority of predator losses I've had are between January and March with my mixed flock.
Second, get some trail cameras. There's likely a lot of wildlife ranging around your property when you're not looking. I've had coyotes walk right up to my porch when I was asleep, and one night the cameras caught one circling around the coop in my back-yard. I never even knew we had bobcats in Georgia until one got caught on camera. Knowing what's actually around you and what times they're active helps you be pro-active rather than just reacting when an attack happens.
Third, realize that predators often change their tactics. The aforementioned bobcat was nocturnal until March last year, then it started climbing trees, hopping over the fence, and killing stray chickens anywhere from morning to afternoon.
Fourth, if you're free-range area is relatively small, consider enclosing it in electric poultry netting and hawk netting. You'll have a happy middle ground of something relatively safer that gives them a bigger space to play in.
Fifth, never think that just because you're out there with your birds it's going to deter a predator attack. I've had hawks initiate or continue attacks with me in the yard, and I had a bobcat grab a stray hen not 20 yards from where I was standing. This morning I heard the flock in "full red alert" and went out to find a coyote pacing the fence and trying to lunge at the guineas through the wire (the guineas, being guineas retreated and then lunged back). Usually coyotes take off when they see me but this thing hung around until I came back out with the 12-gauge and started shooting (so, no more free-ranging until I dispatch the day-walker).