I usually fill and frost the cake the day before the wedding, so there's plenty of time to fix mistakes. Using a serrated bread knife or cake leveler, trim your first frozen cake layer so it is as level as possible. Place the cake on a cake board with about a half-inch clearance on all sides (you can always trim the cake board down if you don't use that much frosting). Pipe a circle of frosting around the circumference of the cake, and then neatly pipe in your filling. Place the next layer on top, and repeat until all the layers in this tier are stacked. Then use your icing spatula to apply a thin "crumb coat" of frosting all over the cake. Put this tier in the fridge for at least 30 minutes to set. After 30 minutes, you can apply your top layer of buttercream or smooth fondant over the cake if you're using it. Repeat with all your tiers.
Now you can attach the stamens. At this point edible glue will probably not be strong enough, so use some high tack non toxic glue such as PVA. For each seedhead you will need four or five small stamen bunches arranged evenly around the head. Glue the stamens to the base of the seed head, squeezing the end tight to the base and the wire to make them stick.
For a bride on a budget, paying a large sum of money for a wedding cake may seem completely outrageous. But what are the alternatives, particularly when you don't have any baking experts in your family? Turns out, making a wedding cake is not as difficult as one might think. There is some significant planning and effort that will need to happen, so make sure you carefully weigh the expense of a cake versus your time (and expectations) as you make your final decisions. And if the cake isn't your thing, you can always serve pie, ice cream, or even an ice cream sundae bar at your wedding.