Richard wrote:

Shirts: Iron them, then fold them like they come in the shop (ie, about
A4 size), and put them in a box file or lever arch file to carry them in
the backpack.

Folding them around a chunky magazine can help, though remove the
magazines before transporting.

Take a week's worth of shirts and hangars on Monday, and when you get to
work hang them up - by Tuesday they'll be fine.

And hence use a shirt you left hanging on Friday for Monday.

Colin