As stated above, let us know the kit you are building – but – the way I plank my decks (whether it be wrong or right) I begin at the centre of the deck longitudinally from bow to stern – drawn a centre line – and lay your first centre plank there – normally called the king plank and this one is slightly wider than the rest of the planks. Then, I glue in the edging planks right around the edge of the decks and I do these in sections I bend them by heating the planks in boiling water & steam BE WARNED THIS CAN SERIOUSLY HURT. Use tweezers or some form of grips to remove the planks from the boiling water/steam and clamp them to a thick piece of plywood/wood with the radius of the plank drawn on. Leave it until the plank cools down.
When I have all the outside planks in on the model – and glued in place – and I am happy – I begin from the centre (king plank) one plank either side. Any deviation of the plank thicknesses can be made up by either slightly thinner/thicker planks width wise. Also, to assimilate the corking between the planks, I tend to use a biro (black ink) do not use a felt tip pin as this tend to run into the grain of the plank and stain it.
I then use a Stanley knife blade to level all the planks off when they have dried and then a light sand with some very fine sand paper. Then I stain with either coffee or old tea bags to the colour I require. Seal the deck with satin varnish (several coatings). There are several photographs in the album of mine entitled Hull.