Is it even possible to set up a system in 12x12 room?

I don’t agree that in a small room speakers always have to be toed in. IME, that is not always the case, and in fact, in my room, I prefer the speakers to be placed straight ahead. (https://systems.audiogon.com/systems/4100) Experimentation is the name of the game here also. The design of the speaker has a lot to do with this aspect.
Also, I do believe that if the equilateral triangle placement can be accomplished, that is preferable.
Lastly, I think that getting the speaker more into the room and off the back wall is going to give you the most depth and imaging precision. Near field listening is the rule in this size of room, there really is no getting around that...which I actually believe is beneficial anyhow.
Rule of thumb...small rooms and small speakers...horses for courses.

I have a 9 1/2 by 14 feet room with 9 foot ceilings so I too am interested in the advice and example setups in this thread.  My speakers are going to be quite large and honestly too big for the room but I'm hopeful that when installed I can get them dialed in as best I can.

Went by new house yesterday and looked at 12x12 room, damn it's small. I have some room treatment from long ago in a box somewhere, can't remember brand. It's not rigged, it is covered in material with reflective on one side and non reflective on other side with some type of batting inside. It has 4 triangle corner traps, 4 4'x1' corner traps and 4 2'x2' panels, never really used them so don't know if they are any good. I have some Corning 703 DIY panels but they will be used in other system so I'm going to make some more. Has anyone ever found a place to buy 703 local, shipping on it is as much as the panels themselves. Does anyone have an idea of how many panels I will need in a room this size. This may sound crazy but I was going to put a leather couch in there but is that reflective also would I be better off with a chair also taking up less air space. I know this is going to be trial and error but I'm guessing this is going to be harder than a normal size room am I correct.

@paulcreed   Cannot help you with home made acoustic treatments, they may or may not work? However, if you look at my system photo, you can get an idea as to how I have placed the room treatments. I also utilize a pair of the excellent Shakti Hallograph's. These tend to focus and extend the soundstage. 
Couch vs. chair...IF you have space in the room with all of the other gear, then I would say it probably doesn't matter. I use a chair, for the simple reason that it gives me more space and it allows me to sit a little higher.
I very much doubt that your new room will be any harder to set up than a 'normal' size room, whatever that is?? BTW, is this going to be a dedicated room..or are you also going to be putting in TV's, beds etc?

No this is a dedicated room, no tv but may put one on later. There will be a lot of gear going between speakers. 2 amps, preamp, CD player and power supply, Linn turntable on wall shelf with power supply, phono preamp, 2 power conditioner one rack mount and one behind rack. Also a tube amp when I want to swap out. Before I used 3 maple 3 foot racks with 3 shelves each, so between speakers it's full but I had more room since  speakers were father apart. I have a couple amp stands I could use to keep things low and get rid of one of the little racks. Dave I noticed you have well tempered arm on your Linn how do you like it. I had a Naim aro but regretfully sold it, I'm now using a ittok 3 and hot rodded audioquest PT 9. Were you able to mount and set up WT arm yourself or did you have to send it off?