Some of the comments made here are totaly one sided.
Some of you are screaming and shouting at "G-EMMA" etc about doing the check BUMPFFICHHL, well whats wrong with considering undercarriage from the start? Wouldn't you prefer to have it installed as a natural reaction to simply consider the undercarriage? It probably takes no more than half a second for the thought to pass through memory whilst maintaining a lookout. As for the hatches and harnesses, how do you know that your pax- possibly small children- havent removed theirs etc.
Someone was moaning about the fuel aspect for christ sake, certain aircraft may require a touch and go on the fullest tank. Theirs that sorted.
And talking about: "why dont you check the cabin crew are sitting while ur at it" etc, well, i think we should keep this general aviation