Measure the distance between each attic roof rafter to determine what size of rafter vent you will need to purchase. Rafter vents are typically sold in 4 foot lengths but need to span the entire area between each eave, so purchase rafter vents that span this entire distance.
Staple the rafter vents directly to the roof decking between each eave. The rafter vent should stretch all the way down to the junction point between the attic roof and the attic floor.
Place the insulation of your choice into the eaves and against the secured rafter vents. Any type of insulation will do, but the rafter vents will ensure that the insulation installed all the way to your eaves will not block air flow through soffits and other vents in the attic.