Love the toilet paper tube idea and I would sure try it, but I'm pretty lazy when it comes to starting the campfire. A propane torch takes just a couple minutes and is still pretty cheap. I will take the time to start a fire the old fashion way of collecting various sizes of small pieces of wood and using paper for ignition, if friends we're camping with bring their children and they want to learn how to start a fire.
This isn't exactly a tip or trick and I'm not trying to change the direction of the thread, because it's surely a good one.................., but maybe it is a tip. Not mechanical, but a human nature, good karma kind of tip.
Here's my tip. When you can, try and create life long memories for children when you go camping. When we first started tent camping 16 years ago we used to bring our son, niece's, nephew and sometimes one of their childhood friends. Whenever we talk to them now as grown ups they still remember the fun things we did camping with them. They're all grown up now and rarely join us camping, but for any friends we camp with that have small children, we take a lot of pleasure in creating memories that they'll remember for a life time. Last weekend we camped with two other couples and their kids. I taught the children gun safety with a BB gun pistol and we shot at cans hung from tree branches. Gun safety was first and foremost and it was the first time any of the children had experienced shooting a pistol. I'm fortunate to have a very gifted family life and doing things like that make me feel like I'm giving something back.