Warding is one of my favorite types of magic. It's extremely flexible and there are so many flavors that it's easy to work into just about anything. I'm always disappointed when games reduce warding to basic shields and 'protection from'-type spells, or ignore it in favor of flashy destructive magic. Immolating your foes at will isn't always the answer. It's practically boring compared to setting guardian spirits behind you to tear apart your pursuers.
I boiled down the different variations of wards I've seen and came up with six general types that spells tend to resemble. Description and flavor-wise a spell could be anything, but the effects and power sources usually fall into at least one of these main categories:
1) Creates a physical barrier that intruders can't pass. This is stuff like magic circles and boundary stones that exclude or contain entities. Anything trying to get into or escape the warded area runs into a solid wall of force that keeps them from entering or leaving the space.
2) Repels intruders with the sight or physical properties of an object. This is "garlic repels vampires" and "fae can't touch iron"-type stuff. There's not a physical force keeping intruders out, but they're blocked by the properties of whatever's set out along the boundary. It might have an actual effect or the intruder might just believe it does, but it's more applied folklore than magic.
3) Repels intruders by invoking a Power to protect the space. This is when the warded area is guarded by a god or guardian spirit that the caster has politely asked to help. Anything that tries to get in either can't, gets thrown out, or has to fight the guardian entity. The key thing is that the guardian is helping because of an entreaty from the caster, not compulsion.
4) Tethers a force to guard a space. This is stuff like the spirits of ancient warriors bound to statues in a tomb to guard it forever. It's the same as 3, except the guardian(s) is there and acting the way they are because of a compulsion from the ward's magic.
5) Makes an area actively hostile to intruders. Things like holy ground or threshold magic, where an intruder either can't enter at all without an invitation or are severely weakened while inside the bounds of the ward. May also burst into flames.
6) Acts as an alarm. Intruders can pass across freely, but it pings the caster or otherwise records their presence. Sometimes acts as a trigger for other spells.
That's it. There are your archetypes. You can break down most types of protective magic and they'll fit into one or more of them. Try it out.
I also thought about why warding regularly gets downplayed or entirely overlooked in games and settled on two main reasons:
First, cowardice. Like I said before, warding is extremely flexible. Your options for using it change with each new space you visit. Codifying how the magic could potentially interact with different architectural elements vs things inside rooms vs open space in a way that produces satisfying rules would be an effort. So designers don't and we end up with boring and generic protection spells. Cowardice. There's no need for that level of exactness and specificity in rules, just give the players things and trust them to have fun.
Second, flavor. Warding is usually complex, static magic with (by definition) sharply marked boundaries. Making wards takes careful planning, time, and precise spellwork because they're supposed to be major enduring pieces of protection. It gives you things like castle cities where the wards have been active for centuries, family homesteads protected over generations, and magic barriers in the far-off wilderness that have barred monsters since before living memory.
It's good stuff and works great for locations the players might visit, but not so well for the players themselves while they're on the road adventuring. Any wards players might use in the field would have to be made fast. Improvised work cobbled together from whatever was lying around or in their pockets. Protections that would serve to secure a campsite for a few days or seal an area of the dungeon so nothing can sneak up on them, but that wouldn't last long after the party leaves.
In that spirit, here are some ephemeral wards made from basic supplies that can be easily carted around and deployed as needed.
1d12 Ephemeral Wards
1) Water from a holy lake or well. Works until it evaporates.
2) Blessed bones. Animal? Human? Something else? Yes! Each have a spirit bound to it that awakens and attacks when an intruder comes within range.
3) A stone. Seal evil entities by way of plonking a big rock on them.
4) Teeth. Summons a ghostly maw to devour unwelcome visitors.
5) Smoke. Creates solid walls of haze between fires burning at the edges of the safe zone.
6) Carved pebbles. Put them in conspicuous places around the area, the sigils on them repel interlopers.
7) A design of footprints pressed into the dirt by dance. Creates a palisade of invisible spikes from each print.
8) Sootblack collected from a sacred fire. A figure made of greasy lampblack tirelessly pursues anyone who crosses the ward's perimeter.
9) Fallen leaves arranged in careful patterns and drifts. Forcefully imparts the idea of gravity to pin anyone who enters the space uninvited.
10) Chunks of empty honeycomb. Houses a swarm of spectral bees. If anything passes by they fly to warn the caster with a waggle dance.
11) Holy texts. Stack them like bricks into a solid wall that'll seal doors and portals.
12) Braided cord made of hair. Delicate and so fine it's almost invisible. If anything breaks it, it starts screaming and won't stop.
(If you'd like more stuff in this vein, Luke Gearing's created a magnificent batch of wards that I absolutely love.)