In a perfect world, every lesson would have a detailed lesson plan. And there would be a PowerPoint, all the resources would be printed off, cut out and laminated. The students would be guided through a range of different activities and there would be clear learning objectives. But let’s be honest, every teacher has been in a situation where for one reason or another, circumstances have prevented them from planning a lesson. And every teacher needs to be prepared to cope in this situation.

For this reason, I encourage the student teachers I mentor to try, just once a half-term - and not with a freshman or sophomore class - the idea of “open-door planning”: the art of being able to open the door to a classroom with no idea what you are about to teach and be able to put together an interesting and challenging lesson as you are going along.

When I’ve spoken to other teachers, they all say it’s often this sort of lesson that students find most enjoyable and these lessons are usually the most memorable. That’s because in these lessons teachers are more likely to try something a bit different, which the students find engaging and interesting, giving them a break from the norm. (Little do they know you are planning as you go).

The great thing about this type of lesson is that it’s fresh; its new activities develop with the lesson, which, depending on the type of class that you have, can almost be led by the students themselves. If you ask students what they want to do they will give you new ideas, perhaps taken from other subjects which you can tweak to fit what you are covering. 

Activities I have developed through this type of planning include:

• Making models of plate boundaries using anything that my Grade 8 students have on their desks.
• Writing and acting out plays with my Grade 7 class about the journey a drop of water would take moving from the upper to the lower course of a river. 
• Poster-making to show the timeline of events of Hurricane Katrina, which then came together as a wall display in my Grade 8‘s classroom. 
• Creating a scale drawing of the Grade 6 students’ desk, including books, pencil cases and diaries. (Talk about stretch and challenge!).

Obviously this isn’t a sustainable way for teachers to plan their week, but it’s not expected to be used like that. However, I know there have been some really interesting, exciting and innovative activities, that have produced great results and good practice to share from this way of approaching the occasional lesson.

Tim Parker is a geography teacher in the North-East of England and tweets from @parkergeog