How do i make charcoal in minecraft properly?

no coal at all to start with? burn a few planks or sticks as fuel for the first log, then feed the charcoal back in. and it has to be a normal furnace, the smoker and blast furnace won't take logs.

logs in a furnace, not planks - that's usually what's going wrong. and one charcoal burns long enough to smelt another eight logs, so it pays for itself after the first one.