Fred and George were the biggest troublemakers of their time, these are some of the lines I think the would be made to write out.
G: I will not charm Prof. Snape's robes bright pink
F: I will not proceed to 'ship' him will umbit- umbridge
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F: The quidditch goal posts are not to be used for a giant slingshot.
G: I will not use first years and house elves as 'ammo' for said giant slingshot
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F: I will not buy inappropriate muggle cartoons
G: I will not attempt to reenact said muggle cartoons with the Giant Squid.
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G: I will not draw smiley faces on the transfiguration desks
F: when asked what the smiley face is I will not answer "not your face obviously. This is much prettier. "
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F&G: I will not flood the great hall up to the neck in firewhisky and proclaim 'Happy Hour' ...
G: I will not levitate professor flitwicks books on which he stands.
F: I will not chant 'These are the hover boards of the future!' While he does so.
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