Hi there, Joseph. Congratulations on making it to the point where you'll be tackling the ruins! Not everyone gets this far in DST.
There are a lot of tips to be made here so bear with me.
Make a base near/in the ruins
This should be self explanatory, but having a base in the ruins is mandatory to farm them comfortably over and over. The minimum I'd recommend is 1 fire pit, 1 alchemy engine, 4-5 crock pots, 1 ice box, 1 bird cage (and a bird), and 4-5 chests.
You may also plant 15-20 saplings/grass tufts, but you can skip that and bring 40-80 grass/twigs from the surface instead. Berry bushes aren't needed as you can find plenty of filler. Especially if you base near the lichen field at the entrance to the ruins which I highly support doing so. Lichen can be used for meatballs and pierogi so you can take care of both your hp/hunger that way.
Bring meat with you
Any meat works well in the ruins. Since you're not rushing the ruins and have supplies, you should prioritize on bringing meat as you have plenty of filler downstairs. A spider egg can work for relatively easy meat.
If you don't have any meat, you can hunt rabbits/moleworms that fall from earthquakes for the safest, easiest meat source. For more meat, you can try fighting small groups of splumonkeys while they're in shadow form or even hunt down depth worms. Depth worms take the most amount of weapon uses for a small amount of meat so I'd advise trying other methods first.
Make a resurrection area
This is kind of a luxury and takes a lot of time to prep, but it can be crucial if you play solo. There's a very high chance of dying in the ruins and (depending on the situation) resurrecting via life giving amulet/lantern may not always be an option.
The resurrection area consists of at least 1 meat effigy, 1-3 fireflies set down on top of the effigy (to offset Charlie's attack timer when resurrecting), 1 scaled furnace nearby (to avoid being killed by Charlie), and 1 backpack near the furnace with these items.
1 weapon, 2 football helmets, 1 lantern, 20 spider glands, 1 life giving amulet, 1 cane and 1 bundle wrap with food if you beat BQ.
Cut down on inventory as much as possible
This tip is more for efficiency but it's probably the most important when attempting to clear the ruins in 1 season of all its loot. Try and carry only what's absolutely necessary as there is a lot of loot to pick up. The inventory of a ruins rusher is a good reference.
Bring a ham bat, football helmets, a lantern, pig skin, grass, twigs, gold, rocks, 25-30 light bulbs, and health food. With this set-up, you can make pickaxes, hammers, and more football helmets as need be. This should take up about 10-13 inventory slots.
I'd also advise having at least 2 football helmets at all times as you will take a lot of damage down there. Preferably 3-4 even. Having just 1 piece of armor is extremely risky as it can and will break very quickly.
A life giving amulet is also wise until you get to the point where you're certain you won't die while farming the ruins. You need to have a lantern as well to make this revive an option since there is no light in the ruins aside from nightmare lights. Be sure to keep the lantern fueled to the max when you can. It'd be bad to die while the lantern has 1% durability and turns off when you need to use the LGA.
Exercise extreme caution around splumonkeys
Splumonkeys are probably the greatest threat down in the ruins once it becomes the nightmare phase. It depends on how many pods your world has, but generally there are too many to handle solo. If you have anymore than 4 shadow splumonkeys, don't bother fighting.
Should you grab the attention of a shadow splumonkey train, there are 2 options for you. 1 is to run until it becomes the calm phase which takes around 5-6 minutes tops. 2 is to run into the ruins and find a rook. They can 1 shot the monkeys and clear them easily.
Dying to or near splumonkeys is terrible as they can steal your items making it impossible to revive unless you have a meat effigy set up in the caves with a permanent light source (scaled furnace). Avoid getting killed around splumonkeys at all costs.
Go after the Ancient Guardian first
It is generally preferable to hunt the Ancient Guardian from the start as you'll probably have the highest sanity/freshest ham bat going in. Entering the labyrinth while being insane is not pleasant as the shadow creatures will constantly spawn dangling depth dwellers. In addition, fighting the guardian while being insane usually does not end well.
If you're not aware of this strategy, you can avoid spawning dangling depth dwellers by moving along the very edges of the labyrinth. This will only avoid them as long as you don't have shadow creatures following you as they will still trigger spiders.
Bring Cooked Cactus Flesh/Cooked Green Caps/Jerky/Bee Queen Crown
Most of the time I ignore my sanity even while farming the ruins. However, being able to comfortably farm while insane is something that comes with experience. The only time I recommend being sane is while going through the labyrinth and fighting the Ancient Guardian.
Some people may advise bringing the Tam o' Shanter, but I'd recommend sanity restoring food instead. Wearing the tam generally means you don't have armor on which is very risky down in the ruins.
If you're still having trouble surviving while insane in the ruins, the Bee Queen Crown is a great option. All you have to do is sit next to a nightmare light during the warning/nightmare phase to gain sanity back rapidly.
Use The Lazy Forager for sinkhole loot
In order to obtain the items stuck in sinkholes, you will need to use the lazy forager. It can be made with 2 thulecite, 3 nightmare fuel, and 1 orange gem at a completed Ancient Pseudoscience Station.
This takes up your body slot which means that you will have to drop your backpack every time you use it. Make sure you have space in your character's inventory when doing this otherwise the forager can't pick up the items.
Also, do not drop your backpack when near splumonkeys. They can steal items out of it if it's on the ground.
Don't repair Ancient Pseudoscience Stations unless...
Your completed station accidentally got broken down by a rook feat. Glermz and Edgy Rick. There should always be 1 completed station spawned by default in DST that is guarded by 4 nightmare lights and 2 bishops.
Also, be very wary when hammering the 2 broken clockworks near the station as they can spawn rooks.
Rooks are useful
As I mentioned before, rooks are quite capable of destroying splumonkey trains and can save you if you enter the ruins during the nightmare phase. They can also be used to hurt other clockworks as they deal 200 damage to anything other than the player.
In addition, they can break down statues, broken clockworks, and incomplete ancient pseudoscience stations for you. Having them break those is preferable to taking them down yourself as sometimes hostile mobs can spawn from all 3 of them. They will aggro onto whatever freed them from their prison at first so you can kill 2 birds with 1 stone using this trick.
Depth Worms can be useful
If you happen to get attacked by depth worms while in the ruins, you can spawn them around the clockworks and leave the area by walking far enough away to have them fight the clockworks for you.
The Antlion is not very useful
I'm assuming you're going spelunking during the summer to avoid the heat which means that the Antlion is a threat. If you are experienced and comfortable soloing the Antlion, I'd advise killing it before farming the ruins. If eliminating the Antlion is not an option for you, the cave-ins are usually not that dangerous but you want to watch where they occur.
If a cave-in happens while you're in the labyrinth, drop the boulders off at a dead-end or hug 1 side of the path. If the boulders fall in the middle of the narrow pathway, they can block you and will consume pickaxe durability or potentially force you to fight spiders.
That's about all the tips I can think of. Of course, there are many different methods to farming the ruins, but this strategy allowed me to clear the entire ruins in 1 summer by myself. I can even re-generate them every year if I wished to.
I didn't include the atrium as I consider it separate from general ruins farming, but I could offer you some tips for it as well if you desire.
Here are some useful videos on YouTube that go over the ruins and strategies for it if you'd like some visuals/additional information.
What YOU NEED TO KNOW Before Entering the Ruins(Ruins Overview Don't Starve Together)
Don't Starve Together → The RUINS (Seven 7ips)
Don't Starve Together → Ancient Pseudoscience Station (Seven 7ips)
Tonic's SUPERIOR Ruins Rush Guide (WX-78) | Don't Starve Together
I hope that helps you to get started with farming the ruins! Be safe and happy spelunking!
