i use a nice piece of fin ply or baltic birch. this allows for was more secure attachment of heavier materials. rather than disguise how things are attached, i use #6 x 3/4" stainless steel sheet metal screws right through the larger pieces.

lighter materials like paint swatches i go ahead and use the hot glue gun or double sided tape. i print up a material description on heavier card stock and screw or glue that down. no leader lines are necessary if your list is logical. if not, we get creative with copper wire or even solder as leader lines.

i've also done the board using full size materials as the actual board. use 12" x 18" a mock up of the siding as the board. then add the other materials or color swacthes right to that. more like a collage of parts rather than a static display on a separate board.

THANKS

make a presentation box...black museum board, black tape to construct it. Or buy a black box with about 2" sides. Iron all your materials to look clean, arrange them to appeal to someone not in your field...make your box say ohhh ahh to someone on the street. Boxes are much better for materials. clients want to touch feel and see close...not attached
on a board