You can use sticky foam pads for a 3D effect or simply glue the toppers to the card base.
Wildflower Bouquets Square Card Toppers for Card Making, Journals, Tags, Floral
6 Flower Barrows Square Card Toppers for Card Making, Journals, Tags, Floral
Set of 6 Fantasy Forest Square Card Toppers for Card Making, Journals, Tags, etc
6 Christmas Cupcakes Square Card Toppers for Card Making, Journals, Tags, etc
6 Fairyland Houses Square Card Toppers for Card Making, Journals, Tags, etc
6 Stained Glass Hummingbird Square Card Toppers for Card Making, Journals, Tags,