My mother taught me to cook, mostly by telling me what she was doing. Now I have her words in my head, so I know to get an onion frying while I think about what to make.
For example, I know off by heart the proportions of things that matter, such as 5:5:7 and three eggs, which means creme together 5oz sugar & 5oz butter, add 7oz flour and three eggs to make a basic cake. It can be cooked in a tin, spread across two sandwich tins or in cup cake cases for fairy cakes. These different options will require to be cooked for different times and temperatures for. The basis flavour can be augmented with cocoa or lemon peel and juice. A glacé icing can be made with Lemon juice and icing sugar or add creme cheese for a softer, creamy icing.
I can read a recipe and know which parts with be easy and what shortcuts will work and which will spoil the overall result.
I'd describe myself as a confident cook for the things I like to eat. I'll check a recipe for something I haven't made in a long time, especially when I know that the proportions are important and I know know them off by heart.
I can confidently adapt recipes for what we have to hand and know what will and won't work. I also leave the kitchen clean and tidy as part of the process of cooking. This for me is the mark of a good domestic cook: delicious meals and no mountain of washing up to be done.
My limit is that I can't be bothered to endlessly meal plan and cook to a budget.
I cook things I like, we eat out a lot (or used to) and eat at the very good restaurant at work anytime I am in.
DH is happy to follow recipes but can't tell just by reading which parts might go wrong or not be quite as simple as suggested in the recipe. His inclination is to use a fresh teaspoon each time something needs to be measured rather than rinse the one teaspoon each time. He appreciates that clearing up as you go along is convenient but doesn't always remember to do so.
DM was defined by her delicious and good value meals. We never put on weight while she was in charge of the kitchen. DF only cooked when she was away and has a very limited repertoire: pancakes, scrambled eggs and a good many chips.