"I never have all the ingredients listed in a recipe."
You do not usually need to have all the ingredients in a recipe. You can swap similar ingredients and use the same technique.
Experiment! You might make some mistakes, but you might also discover a new taste you enjoy.
Use yogurt instead of sour cream, parsley instead of basil, lemon juice instead of vinegar, and honey instead of sugar.
Check out the chart below from Real Simple magazine for common baking substitutions.
Choose a recipe from this website and click on the linked ingredients to find ways to make it a little different.