It really depends on a lot of variables; experience, location, ingredients, season, taste. Starting out it's good to learn measurements then you can advance to

It really depends on a lot of variables; experience, location, ingredients, season, taste. Starting out it's good to learn measurements then you can advance to cooking with proportions and tasting your ingredients to see what works. As you mentioned this is more important in baking, confectionary, things that require specific temperatures etc. Try tempering chocolate w/out a thermometer or baking a croissant 'on instinct' and it'll be a bad time :)