Sprinkle the grass seed over your lawn. You can either do this by hand or you can use a device that you can push that will disperse the seeds evenly as you walk.
Pull out chunks of dried hay from a hay bale.
Separate the hay in your hand to make it form an even sheet.
Lay the sheet of hay over a section of the seeded lawn.
Repeat this process until your entire lawn is covered in an even sheet of hay. The hay will deter the birds from finding and eating your grass seed.