The houseplant murderer: can I become green fingered in eight easy steps?

I have around 20 houseplants – some obviously near death. I called in an expert to teach me how to keep them not just alive, but thrivingI’ve always owned houseplants – but not, it must be said, always the same houseplants.Of the handful of plants I tend to acquire every year, only one or two survive to see in the next. It’s not that I knowingly neglect them: I try to be attentive to their needs, water them regularly, assess their lighting. Every now and again I’ll