If a child does things to get attention, why is it so bad to give them some attention there and then and ask yourself if they need more attention generally? (If I felt ignored and asked for some attention, i'd feel even worse if my plea was ignored).
Ditto leaving children to cry their eyes out when they go to nursery. Conventional wisdom says let them cry, day after day until they learn that it won't make any difference. Why not ask yourself instead if there is something wrong at nursery, or even that the child just isn't ready for it?
My children are long out of those stages now and I did the nursery thing as recommended but it felt wrong and looking back, it was the wrong thing to do.