Note: This whole activity in general is a good job for new players as its not that challenging yet can bring some profits. If you want more refined form of treasure hunting or just looking for more action in general take a look at this: Sierra Caves Complex!
Some says that Wasteland is full of dangers, full of psychos wanting to kill, rape, maim, kill, eat, cook, admire, attack, choke, bake, kill and everything else imaginable. The truth remains that despite all the unavoidable violence, the wasteland is still full of booty. And if you know where you should look for it, most certainly you will find some. The truth is that wasteland is full of countless riches. Guns, armors and whats most important - caps. This all is awaiting for its finder buried deep into destroyed cities (which when taken into consideration that its post nuclear fire America, means practically everywhere). To sum up wasteland is pretty cool place, which you should check up way more often than you probably are currently.
Game wise, in every Urban encounter with enemies there is a chance to find footlocker, wooden chests, ammo boxes or an ice chest. The containers are locked. Those lockers can contain a lot of different stuff. For example traps. For example pair of rubber boots. For example 20-30 bottle caps. Yes as you can see, majority of containers is having pretty much nothing interesting. Except boots, never ditch the boots.
BUT! Not all of them is empty. Some of them are actually containing good weapons, boots, robes, blueprints and drugs. This is why you should be very patient during such treasure hunting. In single urban encounter you can find up to 2 containers with loot (sometimes you will find 0 containers even in encounter with enemies, though most of time its just one crate, the variant with 2 containers or 0 is rather rare. Remember that the containers doesn't spawn in empty location - you need to encounter an NPCs in location otherwise containers can't spawn in that area.) Did I already mentioned traps? I did? Well then lets mention them again. TRAPS. There are TRAPS close to containers and whats sometimes even more tricky there are traps IN the containers.
No seriously, you should remember that most of containers will be trapped. Approach very carefully to each box you find. Some of them will have bear traps around it, others will be protected by anti personal mines. That's not all. After you finish getting close to desired box you should always press "4" to check if container is not protected by built-in trap. There are 3 potential effects of built in trap: "regular" trap with no graphic effect, trap with frag grenade animation and powerful trap with plasma grenade animation. Each kind of trap can cause injuries. The most annoying ones are definitely bear traps which while aren't doing that much of damage are very often causing leg damage.
While graves in towns are always empty, the graves that you sometimes find in encounters are entirely different matter. Such graves (usually being spawned on outskirt of map, they never spawns in location with no NPCs) works just like containers except they aren't protected by locks (hurr, durr!) and traps (no zombies either) are instead protected by mounds of dirt. To loot grave you need shovel or primitive tool. If you encountered a grave for example when farming and don't have neither of those look around for a flint. You can craft a primitive tool using a flint without need of leaving the location. As far as i know there is no karma drop, or grave digger title for looting the wasteland's graves.
Top Loot Area
So you're interested in footlockers haunting and don't know where to start? You would like to ask a question: "What is the best place for treasure hunting?" the answer is easy it is of course - San Francisco! Well to be exact two squares close to San Francisco: 6:14 and 7:14) this area is called "Top Loot Area" and possible quality of stuff in containers which you can find there is a little bit higher than in other places. Of course while browsing this places you will probably get ambushed by Raiders, Bandits, Hubologists, Gang members, Rippers and those 1 or 2 persistent player killers with nick written in Cyrillic but hey "no risk, no gain!".
To be able to comfortable detect containers while doing treasure hunting, you shoud had installed one of two availaible graphic modes which marks the containers.