I use the glue-to-the-LE-then-bend-down and-hold-in-place -with a long steel rule method, but, after the LE has set, liberally wet the sheeting with water before bending it down to the spar.

Water helps the wood to bend, so less force is needed, and the water tends to accelerate the CA so the long steel rule doesn't need to be held for so long. Make sure the bottom of the wing is supported on a very straight building board, and even a slight warp built into the wing up to this point will be straightened out after D sheeting.

David C.