Duvet tips - my strategy is to get the two far corners into position in the corners of the duvet cover, then pick up by the corners and shake it until it all falls into place
Inside out method is propaganda by Big Duvet Cover, the leafy method is optimum.
My tip is to clean little and often, in between doing other things. That way you never get to that awful stage where you need to do A Big Clean because every surface in your home is dusty, sticky, or both.
(you can then do Big Cleans when you feel like it but you never need to)
My tip is for cleaning glass shower doors if you live in a hard water area like me. Spray on limescale remover, smear it about with a cloth or brush or something, then rinse it off straight away.
It took me ages to get to grips with this because my instinct was to leave the spray to work for a while and then scrub, but scrubbing doesn’t seem to make any difference, the spray works instantly and if it starts to dry it just deposits the calcium back on the glass.
Other things I tried that didn’t work - vinegar, microfibre cloths, dryer sheets (apparently good for cleaning glass but not in this case).