There are a few things you should avoid putting in your fire pit. One is garbage. Obviously, this will create a lot of smoke and cause the fire to smell bad. It can also cause the fire to spread if the garbage is combustible. Another thing to avoid is chemicals. This includes things like gasoline, paint thinners, and other solvents. They can release toxic fumes when burned and should be disposed of properly. Finally, avoid putting glass or aluminium in the fire pit. They can melt and release harmful chemicals into the air.