[PeterisP]

Weighing of components. Keep digital kitchen scales on the table and use them all the time. E.g. if you eat breakfast cereal, put the bowl on scales, press button, put in cereal, remember the weight, press button, pour milk, remember the weight. The same for everything you put on a pan. Don't forget to include the cooking oil, it makes a surprisingly large contribution to the total calories of the meal. If you're sharing meals, then you know the "total calories" you put in it, weigh the final product (it generally will be significantly different than what you put in) and weigh what's on your plate - so you know that you ate e.g. 40% of the total. It doesn't take much time (unless your scales suck), but it does take much attention and looks weird. It's a pain in the ass when starting out, but becomes easier when I can just reuse the numbers from when I made the same thing last week.

Some types of meals are easier than others, though - e.g. if you make a large pot of "non-uniform" soup for the whole family for multiple meals, then it's going to be an estimate. It's socially inappropriate to do it at some situations (e.g. if you're visiting your grandma who's providing a meal), but on most days you should be able to track how much calories you got on that single day.

Some restaurants will provide numbers for their dishes, some won't. For takeaway/home orders weighing gives a good estimate - if you don't have the numbers for some kebab or sushi or pizza, then you can assume that it's going to be the same per unit of weight as someone else's similar product, what matters is how much of double cheese pepperoni pizza you eat, not the particular pizza maker.