Ewan Kennedy has posted an article HERE on making oars for the skiff. There are a few basic rules (no spoon oars and no carbon fibre) but otherwise there seems to be considerable variation in the skiffing community.
These oars are simple and fairly cheap to make and anyone with a bit of a workshop &/or basic woodworking skills could make one at home. Ewan has roughed out a design, but comments and suggestions are invited.
(click to enlarge)