I learned about marcotting (air layering) when I was in primary school and it has been ages since I've seen anyone propogate plants this way. Marcotting is one of the oldest forms of plant propagation and it is mostly practised in South East Asia.
Someone in my neighbourhood has tied several parcels of compost on his guava plant. After a couple of weeks, it's quite exciting to see some development. The root system is now visible through the transparent bag. Soon he will be able to transfer the marcot into the ground.