Checklist for Take-off and Landing

We have had many disasters when moving away from site e.g. Not raising the jockey wheel etc. so for many years we have had a pilot's style checklist - you know it makes sense. With the new van we had to add "switch pump off" as it has an internal pump which can in theory run dry but we don't want to risk it. Switch off gas, close roof vents etc.

What is first on your list?