Location.
They will live near a water source, and probably near their fields...
Neolithic hill forts are fairly common. It's a walled village atop an artificial hill, built on the floodplain. It may also have a cistern and/or a well down through the motte/tel. Walls are likely wood, possibly also dry-fit stone for part of the height.
I can tell you from personal experiences in the SCA: Fighting uphill sucks.
Thus, hill forts are an important element of location; when practical, they will be used.
Other variations on location include hillside villages like the Anasazi (and Hopi) used, and inaccessibly high villages like in the Andes, swamp-surrounded villages like old Tenochtitlan, and desert oasis cities all are inherently defended by the trap-like terrain.
Livestock
They will have some livestock in the village at almost all times. Not all of it, but easily a weeks worth of food.
The rest of the livestock is generally close to the village...
Remember:
- Cows, espeically in numbers, can be dangerous in their own right. Especially with persons they don't recognize. That means the PC's.
- Sheep, pigs, and goats can be downright nasty fighters and quite territorial, in addition to typically being present in significant numbers when present. And a single unhappy sheep or goat is a danger; and unhappy pig is a lethal trap in its own right.
- swans, geese, and loons (all kept as food birds in pre-modern Europe) make pigs look downright friendly. ²
Troop positions
Archery and/or slinger positions on the walls. The raged weapon guys firing down get extra range and damage out of the deal, making fighting uphill suck even more.
In societies with a single handedness dominant, the accessways will be configured for that handedness to swing against those entering, but to impede swings by those who are entering.
Absent things
What they won't have is long-standing traps away from the gate and/or just outside the walls. It's too much a problem for the locals. They also won't have much in the way of mechanical traps. Maybe a swing-log¹ into the gate area, just to beat the snot out of the guys trying to batter the gate down, but that's able to be kept pretty safe, and doubles as a bar on the door.
They also won't have pit traps anywhere near livestock. Too much risk.
Any traps they do set will most likely be temporary, and manually operated. Snares as temporary traps, sure, but only when the cattle, sheep, pigs, goats, and rabbits are contained, or in areas those won't go.
¹: Best exemplified by some ewok traps in SW:ROTJ.
²: I watched a guy dragged off to the hospital by the police when he attempted to break into a friend's home, which had a goose resident. Goose broke both his arms, both his legs, and half his ribs. Oh, and Goose, swans and loons will all imprint on just about all the yard animals, and so if you attack any animal they think of as "family" they will defend that critter.