Child Me! is a tiny plugin that adds a nifty shortcut to structure sections and category indexes, making it easier to create new child elements for a particular parent (i.e. no more having to manually select the parent element in the child element's editing page).
As a bonus, if a structure section has more than one entry type, Child Me! makes it easier to select the correct entry type the child entry should use as well.
Docs/usage info here