You root them pretty much the same as I do. Over the years, I doubt I have had 50% success in rooting these fiddleleaf cuttings whereas I have close to 100% success when rooting plumeria cuttings. For plumeria, I use either 100% coarse perlite or a mix of 50% perlite and 50% fine fir bark. It seems to make little difference with plumeria. Now that I air-layer the branches, my succsss rate is close to 90%, but it can still take 2-3 months to get a rooted branch. Ken