There were techniques they could employ for controlling warping that are not as common today: at least, not in carpentry.

First, they could rive the wood, split it instead of saw it. It would not be practical for something long, like floorboards, but for shorter lengths of shingles and panels it was faster to split up a short log with a froe and maul than to saw it, and as the split billets would follow the grain, they would be less likely to warp. But that also meant the log had to be selected: it had to be wide enough, to make decently wide shingles, and had to be free of checks, twisted grain and reaction wood, that would make it hard to evenly split. And it had to be an appropriate wood. You can split red oak very nicely, and it resists rot. You can't split willow, and it has the rot-resistance of fresh fish.

Second, they could split in quarters or quartersaw the log. A board that's quartersawn will not change shape as it shrinks and swells during the year. Again, that meant the log had to be selected: twisted grain would make a board that would still warp. And it would waste some wood: plainsawing a log resulted in more planks, and if the sawing is being done by sawyers, in a sawpit, it's nice not to throw away off-cuts.

Once they had sawn up a log into planks, or trimmed into a beam, they could and would season the wood, put it under cover somewhere, like a barn. Someone making barrels or clogs, for example, would typically get green wood that had been split and trimmed into rough staves or billets, and it'd be put away to dry and used when seasoned.

They could also design to allow for wood movement. The classical post-and-beam barn structure did not have to be made with perfectly dry timber. Though the mortices and tenons were tighter if the timbers were dried for a while, the structure could tolerate some warping and checking. Log cabins were even more tolerant, which was useful: shaping green timber with edged tools is a lot easier than shaping dried, and a cabin required a lot of logs.

On a small scale, furniture could be designed to accommodate wood movement. The classic wainscoting, frame-and-panel door, frame-and-panel shutters, etc . all could use a panel ( in old English furniture, typically a piece of quartered, riven oak carved or planed flat on one or both sides) set in a grooved frame. The panel could shrink and swell within the grooves, over the seasons. It might get loose enough to rattle a bit, in the dry winter, and swell to fit snugly in the damp summer. And, again, the wood would have to be chosen, assessed. But there would be so much effort required in creating boards, posts, panels, etc that the effort to select and plan the cutting of them was quite natural.