I use a couple of skew chisels. You can also use a fishtail chisel (I think Lie Nielsen are the only ones making these at the moment) or some fine bench chisels.
The skews are my favourites and are made by Kirschen under their Two Cherries brand. They keep and edge really well. When honing or re-establishing the bevel you need to use the Veritas MKII Honing guide with its skew registration jog - both of which I own. It's easy to do with some practice.
|Two cherries 1/2" skew chisels|
|Pare to the centre of the board and make sure|
you don't let the non cutting side touch the other
dovetail. Otherwise you will have a chisel shaped ding to fill
|Always use you square to make sure that you are level and nothing stick up|
beyond the base lines. If it does pare it down again.