Replace water with milk or buttermilk
Use melted butter instead of oil
Add an extra egg or just the yolk
Add vanilla extract
Add sour cream or Greek yogurt
Add instant pudding mix
Use coffee in chocolate cake
Add a pinch of salt
Add citrus zest
Add spices like cinnamon or nutmeg
Mix in melted chocolate or cocoa powder
Fold in chocolate chips, nuts, or fruit
Brush layers with simple syrup
Frost with homemade frosting
Add a filling between layers
Bake in the correct pan size
Do not overmix the batter
Do not overbake the cake
Let the cake cool completely before frosting