"I'll do it too". Pupils may become more motivated in a timed or independent assignment if they see that you, their teacher, are doing the same thing.
Set out the instructions for the task and put yourself in their shoes. For example, begin with "Before we start, let's discuss what's worrying us, ie, we don't know how to start" (a common one in the English classroom) or that "we won't have enough time" (possibly leading to some collaborative planning before embarking on the task).
Once you all understand the instructions, undertake exactly the same task as your pupils under exactly the same conditions. As you perform the task (for example, a timed analysis, set of comprehension questions or piece of creative writing) jot down any problems you encounter and use them as a basis for a plenary summing up.
This technique can be extended by copying your work for the class for the next lesson and, if you are feeling particularly brave, allowing them to critique based on their knowledge of what constitutes success in this type of activity
Kerry Hopkins is head of English at The Grammar School in Leeds