[31 Woody]

Do the curtains already have grommets in them? If the grommets are located in the curtains, I would center the curtains up on the appropriate window openings and then mark the wood where the attaching pins go. If the grommets are not in the curtains, I would install the grommets first, then locate the attaching pins as previously mentioned. My reason for this is once the pins are secured to the wood, it is far harder to mark where the grommets get positioned and install them. If the wood has holes already and the curtains do not have grommets, do what Tom said.