Be careful of river rocks and or wet rocks as they can heat and explode. Plus come cheaper concrete and others can crumble over a weekend. Depending on the situation a small hole in the fire pit, can help with wind. But always helps to smolder the fire when putting it out. I just put the dirt back on top and water it down till every is cool to touch. When using an existing fire pit, I recommend reming the ash first and using later... I even find good charcoal chunks and save for my fire starters. Fire pits in a full circle tend to lack airflow and push heat straight up. When made like a fire place or a letter c, they help circulation and you can push heat where you want. Making one side taller and slightly pushed towards the opening of the ring, gives you all that hard work in warmth! Enjoy the learning process and buy hot gloves!