I use Timothy hay that has spoiled as a brown, I also use old straw (hog bedding), over the last two years I have never had either act like it should be a green in composting.
I use heaps and have a tumbler that has not been used this year, a tumbler (container) is good if you want to keep the compost pile out of sight (but carpet or tarps work fairly well for that too), or if you need to speed up the decomposition process.
When I am building a heap I use 2-4 inch thick layers starting with a browns layer, I build up to a 4-5 foot height (this is dependent upon your height and comfort when building a heap) and the foot print is 4 feet square, round works just as well so it really is your choice.
If you want a heap to heat up really fast or get really hot then you want a large green core surrounded by lots of browns.
You also want this heap to drain excess
water easily and you will want a cover over the entire heap (this holds the heat in so it can get above 160 f)
Keep in mind that fresh grass clipping put into a black plastic bag, sealed and left alone will generate
enough heat to have spontaneous combustion at which point the bag will explode.
So, to get a heap really hot, think along those lines when building your "Hot Heap", and remember that it is possible for it to catch fire, place appropriately, as in away from any thing you would hate to burn
I build hot heaps for composting meat and meat byproducts, bones, etc. I use two layers of 6 mil. black plastic as the cover on these heaps and they are placed in an open area just incase they should catch fire.
I am 6'2" tall so 5 feet is a workable height for any compost heap for me, comfort when working with a heap is often an overlooked consideration.
Many people say compost piles need to be 4 feet tall, but if you aren't tall enough to work the heap when it needs air, then it could be anti-beneficial.
A heap that is a 3' foot cube will work fine, heaps do not need to be contained but it helps make your composting area look neater (complaining neighbors are avoided).
If you want an easy to judge way to build heaps, most
pallets are in the 4' square range, so if you build a box out of pallets by tying them together then you have an automatic measurement.
If you should find you need more nitrogen you have options;
pee is high nitrogen, coffee grounds are high nitrogen.
Contrary to popular sentiment, you can compost meat, you need to prep it correctly though so it breaks down fairly fast and your heap needs to get really hot.
Animal draw and the possibility of pathogens are the main reasons most people don't compost meats.
In China they have been composting meats & human wastes for centuries, it just requires the above "Hot Heap" method.
Air is the main reason people turn their heaps, if you build a heap with enough rough browns you can get away with a no turn heap that won't go anaerobic (fermenting compost, that was not meant to ferment, is a stinky heap).
Compost heaps can be as large as you want, check out any commercial operation, their heaps are huge. In the compost world any heap smaller than 3' cubed needs to be in a container, otherwise it will not work very well or will take forever to break down.