In definition the donor cannot receive any goods or services in exchange for the donation. Nonprofits can sell goods or services, but those who purchase them are not able to get a tax write-off for the transaction.
This means that any perks the donors receive become a step removed. Yet there are still real and tangible perks. Many of these perks exist because most donors are also involved with a nonprofit and therefore benefit directly from their programing. It could be an after school tutoring program, youth sports, boy/girl scouts, alumni associations, professional associations, religious organization, and many more.
When giving to a nonprofit you don’t directly participate in you benefit from the good work that organization performs in the community. It is similar to the general benefit we all gain from funding schools and universities. While you may not have children enrolled yourself having an educated population benefits you everyday.
As Kristin Winkler Snow wrote below there can also be specific perks attached to donations. A lot of these example would be driven by larger fundraising campaigns and are good ways to motivate larger donations.