Prepare your cake according to directions on the box. Let the cake cool completely.
Wash berries, and cut strawberries into halves or quarters.
Once the cake has cooled, assemble your mini trifles.
Add small pieces of cake (cut into cubes) to the bottom of your glass or trifle bowl.
Add a layer of berries followed by a layer of whipped cream.
Top with berries for garnish.
If you're making a large trifle, continue to layer until the bowl is full, ending with whipped cream and fruit on the top.
Serve immediately.