When a recipe calls for specific vegetable measurements, cooking oil, grated cheese, this is easier than it sounds, measurements not needed!
If a recipe calls for 1/2 cup chopped onion, be easy on yourself, just chop a small onion.
I have seen recipes that call for 1/2 or 1/4 cup of diced bell pepper, just dice a whole bell pepper, no one is going to notice, after all, what are you going to do with 1/2 a pepper? Sure you can make an omelet the next day with a diced pepper, but a whole pepper would be better.
When a recipe calls for say 1 tablespoon of oil for cooking say some chicken pieces, a splash of oil is fine, no need to measure that.
For cheese, go on the plus side, if a recipe calls for 1 cup of grated Cheddar cheese, go with 1 1/2 cups or more, this goes with any cheese, cannot go wrong with more cheese.
Recipes are made to be adjusted, not held to word by word, adjust as you see fit. That is the beauty, be creative!