You want to have the skin come off of the frame for storage, and also go on easily. Designing it so that it is held on with a "shoelace" is a very practical method. You undo the lacing to remove the skin, allowing you to dissassemble the frame. When getting into the water you reverse the process, assembling the frame, slipping one fitted end ( probably the stern) over the frame, then pulling the excess fabric over the bow, and lacing it shut on the bow deck, where you can keep a good eye on it while paddling.

Depending on how you lace it, you'll have some interesting variations.

You might lace every other hole with bungie cord to draw the fabric taut, while lacing the remaining holes with nylon or polyester cord for safety, should the bungie break.

Extra grommets can be added for running deck bungie cords, and those will also draw the fabric a bit tighter.

The fabric won't stretch a lot during just one day on the water.You lace it up in the morning and pull it out at the end of the day. If it is loose, lace it up tighter for the next day. If the knot for the lacing is by the cockpit you might even tighten it while you are on the water! I'd suggest you only do this if there is a second lace holding the fabric closed, and you are just adjusting one lace at a time.

Design your kayak skin so that there is excess material at the bow that can be folded, at least three folds, for a waterproof seal. Stitch on a row of cloth with grommets in it to the left and right of where these folds will end. Then, after making a waterproof seal by folding the flaps of cloth, you lace up the grpmmets and they dray your sewn cloth over the folds -- holding everything together. If you want to put on a vecro-edged piece to cover these cords, go ahead. otherwise, they'll splash up about as much water as decklines on any other boat -- which should not be very much, nor be very distracting.

This may actually save you a bit of sewing, and make fitting the skin a bit easier.

Hope this helps

PGJ