This is actually a lot of fun, although it can be easy to burn your fingers so be careful. It is also a good idea to do this over an existing fire pit, or somewhere where fallen embers will not pose a risk
Once you have a good safe location, start by grabbing a thick chunk of wood. Dry dead wood is best since it burns faster, plus cutting down a live tree to make a bowl is a terrible thing to do. Don’t do that. The easiest way to find a good piece of wood is to just use a large piece from the bags they sell at the campground office. You can use this “as is” or you can even saw it to form more of a square shape. More detailed carving and decoration can take place after the fact. Just keep in mind that once it is shaped, it will need to be able to stand up on its own, without tipping over
To start the bowl-making process, you’ll need a red-hot ember, a tool to reach and pick up the ember, a lot of lung capacity, and some patience.
Start by finding a flat surface on your block of wood, and place the ember on top of it. The idea is to have the ember burn a slow indent into the wood that will eventually enlarge into the bowl cavity itself. Gently blow on the ember to heat it up, being careful not to blow it off of the wood. It may be helpful to find a small item to hold the ember in place.
With a bit of patience, a lot of breath, and some luck, the ember should start burning its way into the wood. Once a small cavity begins to form, it becomes much easier to keep the ember in place, and from here it comes down to positioning and patience. In fact, you may not get all of it done at once. A large bowl could take several hours to develop.
Once your bowl is as deep as you want it to be, remove the ember and start cleaning out the cavity. For this you can go all-natural and use abrasive material like sand, or you can go and buy some sandpaper and make things a bit easier on yourself. It is up to you to shape the outside of the bowl. Wood carving tools are a great way to go, but you can spend a bit of extra time and just whittle away with your knife.
However you go about this, it’s a lot of fun and a great way to keep yourself busy during your camping down-time. But be warned: Finishing a whole bowl can take a long time.