Hello -
The flower nail trick is to simply grease it however you grease your cake pan and set it upside-down in the cake pan. Pour in your batter, and bake as usual. The flower nail conducts heat up through the middle of the cake as it is baking, helping to keep it more level.
Wilton Bake-Even Strips are cloth strips that you soak in cool water and then apply to the outside of your cake pans. The wet cloth slows the transfer of heat from the sides of the cake pan, resulting in a more even baking of the cakes.
Hope that helps!

Sherri