I cook in a variety of ways really, but there are a couple of constants.
I will always chop and measure out things in advance, so when a recipe says add this, cook for 2 minutes, add this, I am prepared. I will also measure out all the herbs & spices that go in together into the same container and effectively pre-mix them. The same with all the veg & other produce, so if carrots and celery go in together, then they will be chopped and stored in the same container.
I won't necessarily stick to the quantities of herbs & spices, or for that matter the veg. I'm not one for 1 cup of chopped onions. 1 medium or 2 small onions chopped is fine by me. The same for most things 250g of mushrooms when I have purchased 300g is not going to happen, all 300g will get used. If I have 25g of pasta left over in a packet, it will get added with the rest of the pasta the recipe asked for... and so on.
I virtually always cook for more than 1 day. Few recipes are 2 person recipes and it makes life easier if more than 1 meal is prepared at once. So if we are having an stew, and it serves 6, I will cook for 6. We will eat it hot that night, then reheat 2 portions the following day, and 2 more the next. I won't reheat all 4 portions on the 2nd day (hope that makes sense).
If it is a main meal that isn't soup/stew/casserole (UK version) etc, then I will sometimes cook a side (though I don't think of it as this) to go with it. So lasagne can or can not be served with additional stuff. It depends largely on what is in it and how many nights I want to 'pad' it out for.
Dessert - that depends on what is planned, how big our main meal is and how filling it is going to be. It varies but usually there is no dessert simply because I watch our calorie intake like a hawk at the moment very aware that neither of us are cycling or doing much extra activity compared to how we normally are (we are, minus broken ribs that is) normally very active but this last 2 years have been difficult with my back and the paralysis and coming to terms in the change in our lives).
One pot meals or multiple pots - again it depends on what is being prepared. We plan our meals out in advance the week before. So if I plan an Indian dish that needs 4 pots, all 4 will be used (I have been known to need more than the 4 rings and have to reheat things or keep them warm in the oven). I often prepare something instead of sliced bread to mop up soups/casseroles/stews or to go with an indian meal such as homemade chapatti - really easy to do, vegan naan bread or even just an experiment with a new recipe like last week when I made the spelt bread with orange juice.
Small appliances or the stove? Well I don't have any small appliances that cook meals - everything is the stove or the oven, end of story (the only exception could be classed as the pizza oven we have outside now we live in this house but it is neither small nor an appliance, though I have cooked our meals in it or my Excalibur dehydrator when in summer I make 'cold' meals for evening meals.) I don't have a slow cooker, I don't have a rice cooker, I don't have....
I also very rarely freeze anything that is additional because of the way we cook and eat. I certainly wouldn't cook and freeze veg unless it was a case it was going bad that night and needed cooking to keep it 'eatable' and we already had something cooked, but I would consider that to be bad planning on my behalf tbh.