Bucket of grain, shake it - most will come running!!! If you can get them into a round yard or smaller paddock that would be ideal, as after 3 months of freedom most horses won't be too keen on being haltered
If they are resistant to the above you may have to consider constructing a temporary fence to create a small area in which to first contain them and then allow you to work on catching them from there. It may take pushing/working them to where you want them. Is there free flowing water/water in more than one location of the paddock? If so, that adds a challenge - if not, you can use the water source as the location for your smaller area as you know they will have to enter that smaller area when they want water. Even if there is free flowing water, you can use other "bait" to get them into your smaller working area. If all else fails, you can drive them into the small working area.
I train mine and any new ones to come in by pairing honking a horn with getting some grain. Some of our pastures are a few thousand acres.
Honk the horn, go look for them. Honk when I see them. Get closer. Honk when close enough for them to see/hear grain in bucket. They come close. Honk right before doling out the treats. Only takes 3 or 4 times before they come running in when they hear the horn. Most here have a smaller overnight pen, some corrals, or a small couple acre paddock we catch into.
Silly me, I used to try to whistle or yell to them. A neighbor used his truck horn, too. Until it quit. Then he bought an old trumpet at a pawn shop and sqwaks loudly on it. He's hilarious. It works with his cows, too.
If you have neighbors close by, maybe you should warn them if you try this. :)
To Donovan a 1000 acres forms a 'paddock' - which to we Brits would be maybe 1/2 to 5 acres before we had a 'field'.
Indeed I wonder the word for a 1000 acre (????) is in English English. I do know you'd have to be a multi millionaire Lord to own it. I also wonder how many 1000 acre (???s) , undivided by fencing , there are in Britain. There can't be many. Maybe the Queen owns a few.
Obviously I was born on the wrong continent.
As for catching the horses - sorry can't help. I,ve never known the problem.
Barry, we have multitudes of open space in Australia, it is not uncommon for cattle stations central Australia to be thousands of hectares in size. This is because our land is not as fertile as that of much of Europe. Once you get a couple of hundred km's from the coast, it tends to stop raining nearly entirely, most of the plant life is salt bush, scrub and stalky grasses.