Working with plants is like working with children.  Plants, like people, do not always follow hard and fast rules.  In this book I tried to give helpful hints based on what I have learned from research, expert advice and from making terrariums for well over a year.  However, the most important rule to follow is to treat plants as you would a pet - with a kind word and a gentle hand.  With this in mind I don't really see how you could fail.