If your project management process implies creating many subtasks, it could be very productive if subtasks inherit some details from the parent task.
For instance, if you want the subtask to inherit subject, description and version from the parent task, please follow these steps:
- install View customize plugin
- create the following view:

Copy/paste code from here:
$(function() {
var addLink = $('#issue_tree a[href*="/issues/new"]')[0];
var subject = $('#issue_subject').val();
if (subject) {
addLink.href += '&issue%5Bsubject%5D=' + encodeURIComponent(subject);
}
var description = $('#issue_description').val();
if (subject) {
addLink.href += '&issue%5Bdescription%5D=' + encodeURIComponent(description);
}
var version = $('#issue_fixed_version_id').val();
if (version) {
addLink.href += '&issue%5Bfixed_version_id%5D=' + version;
}
})
Done! From now on, your new subtasks will include subject, description and version from the parent task.