Before doing anything else, you should think about your experience of the text type in question:

• from your personal interests and reading
• from courses you have attended in the past
• from previous experience of teaching this text type

Next you should consider the children, their curricular targets and the outcomes of the last unit for the strand or this text type. For example:

• Characterisation in narrative was a particular issue from the last piece of narrative writing that the children did.
• Many of the children's writing targets relate to sentence structure.

Whilst shaping my ideas you should continually think about opportunities to develop these key areas: when and how can I teach to the targets?

Finally you should consider contexts:

• Are there any obvious and meaningful cross-curricular links you can exploit? - possibly already mapped out as part of the wider curriculum.
• Are there any whole-school themes you can tap into?
• Are there any appropriate topical contexts - either local or global?
• Might you ask the children of any links they can make?
• Might this unit of work link in any way to a class novel?