I differ on the uniform.
I have 2 pairs trousers
2 jumpers
5 t shirts. They don't have logoed ones so just plain.
DS seems to keep his jumper on, so I am constantly washing the jumpers, whilst the t shirts remain pristine.
Next year I will get more trousers and jumpers and the same no of t shirts.
I am a big fan of shorts though. As they are shorter there is less fabric to get dirty so less washing. I have upgraded and got 3 pairs for this scorching summer we are having. He will be in those to November I I have anything to do with it.
Other tip is John Lewis click and collect from local Waitrose. Similar price to M&S but I could actually get the sizes I wanted and i'ts free returns.