I start my AV leaves in vermiculite. The leaf already has all the nutrients it needs to grow roots and shoots. Vermiculite has practically no nutrient value, and therefore no nutrient value to harbor disease, either, and naturally provides a semi sterile environment so the AV leaf can grow through the vulnerable stage without problems.
Put the moistened vermiculite in your container. Plant the leaf. Water to settle the vericulite. Let the pot drain for at least an hour. Put the pot on some paper towels and watch more water come out. Seal it up in a freezer bag, put in bright light but no direct sun. No need to do anything more until you see sprouting.
This is just the way I do it. There are many other successful ways, too.
