I absolutely adore this question and I adore you anon

It definitely has to be bill or Charlie because they’re the oldest and have been doing it for so long. I reckon bill says he’s the best but Charlie actually is just because he seems like the type of person to understand the dynamics of a good blanket fort rather than just relying on experience.

However!!! I feel like this is a competition in the Weasley household and randomly, Percy ends up being really good at it and everyone is just so shocked but also so happy