Mr Shady, I made curtains for our Triton and made them traditional way with blackout linings, it was pretty successful but if I were doing it again I would make a couple of changes.
One - be careful h ow thick your curtain material is because with lining fitted as well it can all get a bit bulky fitting it up under the pelmet.
Two - I would sew the blackout lining edge to edge across the whole curtain so that when you pull the two curtains together there is not a strip in the middle with no blackout and the light peeps through the thinner layer of just the curtain turned in edges
Hope that makes sense, maybe a bit technical for you and Mrs S will know what I mean