I've heard of air layering, but I've never understood exactly what it's for. I gather it's mainly for difficult-to-root plants. What does air layering do for tomato plants? They aren't difficult to root.

I have a hard time with cuttings. I also get bigger healthier plants through air layering.

There's air layering, and layering - 2 different, related, methods. Each has its place. For tomatoes, I know you say you have a hard time with it, but keep practicing taking regular cuttings. Once you get the hang of it, you'll wonder why you had such a tough time earlier. :-)

I also like that in air layering the plant keeps growing while rooting. It also takes much less space.