Go to the main board, make a new post.
In the dialogue box there is a drop down that lets you select whether it's a normal post, or which image challenge it is for.
(FoldsFive, Fri 27 Nov 2009, 8:18,
archived)
Don't forget the other seven steps.
(FlapjackI spay a little mare for you, Fri 27 Nov 2009, 8:20,
archived)
It feels pointless repeating them now, what with you having relayed them so well.