If you're in a hurry for compost (not likely this season, but who knows?), turn this one and start a new one.

If you're not in a hurry, you can just add more materials as you acquire them, turning and mixing them in. The compost heats because you've got an explosion of microbes (a good thing). If you want to add more ingredients, the microbes are already there and ready to start on the new stuff.

You can also 'inoculate' a new pile with mostly-finished compost to get things off to a quicker start.

Composting only has a few basic rules, and most of that involves not adding so much of something that it throws off the natural balance. If you've got something approaching the correct mix of carbon (browns) and nitrogen (greens) and it's heating up without stinking, you're doing just fine.

Compost has been known to catch fire under certain circumstances, but the size of the pile is always larger than 7'x7'x7' (like a barn full of damp hay).

Sue

If you have more space than energy, just add layers.

When I have a lot of material I prefer to add to the sides to build a long pile keeping it at least 4' wide & tall by however long you have materials to build it. Building a pile wider than 5-6' makes it too much work to turn & the outer parts don't actively compost anyway.

If you build your long pile you can turn it all to the left pulling middles out & the outer parts inside the pile. Then your next turn is to the right & so on. It's a great workout to turn compost piles & a pitchfork helps. I've used a hoe as well sometimes after at least 5 turns or so it gets easier because the materials are smaller. Either way, turn left & leave it for a few days or a week, then turn it right the next time. If it doesn't keep heating after a turn or adding moisture you'll need to add more greens in whatever form you have available.

It seems like 100% leaves are slow to compost, but if you've shredded them & mix with the green grass clippings it speeds up. Use what you have around to cover it like a tarp, upside down old carpet, wet cardboard, feed sacks, or burlap bags.

Again it's either energy, time or space that limits your composting projects.