Cups, half cups, third cups and quarter cups are all standard volume measures (as opposed to weight). You buy a little set. You can even get cup measures that come with a sieve attached.
Tablespoons, half tablespoons, teaspoons, half teaspoons, quarter teaspoons, etc. also come in a little set and are standard.
I never sieve flour no matter what a recipe says.
As a rule of thumb, never pack flour or cocoa or other flour type ingredients (like ground almonds) when following an American recipe. Just scoop with the cup and level off with the back of a knife.
American brown sugar is nearly always packed in a recipe, the reason being that it is moist/lumpy (not like demerara sugar) and therefore won't always fill the measuring cup with no air pockets unless you squash it down.
Granulated sugar flows and settles, so never packed. Demerara sugar also flows so needs no packing in.
You don't have to measure butter or marg because sticks in a butter or marg packet (4 sticks per pound) are usually packaged individually in wax paper with markings showing the tablespoons -- eight tablespoons per stick, four sticks per pound.
Interesting to hear the comments about German shelf loos and the reason for them. One of my grandmothers spent a year or two in Bavaria in her late teens way back at the turn of the twentieth century. She hated it and thought Germans were vair uncivilised (apologies to Germans) for various reasons all to do with poop and food hygiene.
Gaps --
Nobody looks. Nobody is remotely interested in what you may be doing in your cubicle. Even if you happen to catch a glimpse, some form of cognitive blankness descends and it isn't registered.
PetulaGordino -- there is nowhere hotter than KC in summer imo. I spent the heatwave summer of 1988 there but even in a normal summer the heat wallops you.
Thank you CarolDecker for explaining one of my top Things I Need To Sort Out.