I use a bit of this and a bit of that. Going by taste more than what a recipe says, because I like things to taste good to me, not just to a specification. If I want to make something and I don't have a particular thing, I see if there is something else in the pantry I can use instead. Usually, there is a good substitute. Like tinned tomatoes in the food processor if the recipe calls for tomato paste or salsa and I don't have any. I have substituted cream cheese for cream and dried out my own bread in the oven to make bread crumbs. I have three little kids, so I guess that has made me more creative than I used to be, because the thought of heading out to the shops with three little hungry kids just to get one ingredient, and have to walk past the virtual mine field of sweets that are on display just at eye level, really make me prefer to take another look in the depths of the pantry for a substitute.
I have always been what is termed a 'creative' cook! Right back to when I was doing Home Economics in high school,when I would forever be getting told off by the teachers,until they tasted my dishes!! My son has always been just like me,starting to cook beautiful meals at just 9 years of age,and going on to become a chef as soon as he was old enough for an apprenticeship! I can start using a recipe,but inevitably,I will add something else to it,or delete an ingredient! Having had severe allergies all my life,I believe that this has added to my creativity,just so I could still work out something yummy which I would not react to!
I like to stick to the recipe the first time I make a meal, so I know what it's supposed to be like. If I like it or I think it could be made better, I tweak the recipe the second and subsequent times I make it.
I live alone so cook just for myself most of the time and frequently 'improvise'. If I have visitors (which is very rare these days as my friends and I find it easier to go out for meals when we meet)...I then would use a recipe if I wanted something a bit different,
When first married, I stuck to the recipe like glue.
For much enjoyment, read:hobby, I attended many Conventional & Mocrowave Cooking Classes, as I loved/still love Cooking!
My Grandmother & Mother taught me how to cook at home. They were just SO good; my Mother, in particular, her Dinner Parties were legion!
As time wore on, I improvised, & do that to this day, with great results!