So presumably the Haydn is the only one needing any sort of major consideration? Looking at our edition of that (ABRSM, lousy binding which makes it difficult to lay the music flat

), the first turn is timed so that the right hand has one beat rest, and probably is intended to be used for the flip - the second turn is very awkwardly scored, so I'd be inclined to copy the last page. What I do is tape the copy to the edge of the previous page: if the music looks to be wider than the stand, I use my carboard support thing - a sheet of card big enough to support all three pages - behind the music.
Another tip for easier turns - I use the strips of plastic post-it stuff which students use for marking pages - they're removable, and by sticking one to the bottom or top corner of a page one side, and another the other side, so a little bit of sticky from each tacks onto the back of the other, you get a good tab to grab onto for a turn. The packs of tabs I get come in different colours, so if I've got lots of turns, I have several different coloured ones one above the other, which is eyecatching and also helps.