Hello pieman, I have had best success with soft green cuttings by just putting them into a good potting mix(which usually has some perlite in it already). I water them very sparingly, and keep them warm, and after a while they develop roots. You will know if they fail because the cutting will get a brownish color and get even softer than before. As long as the green cutting remains green and firm, you can be reasonably assured that things are doing Ok underground. Good luck.