I think for the addition order I cannot avoid the hard way:
ClearAttributes[Plus, Orderless]
while for the product terms:
Replace[expression, Times[x_, y_] -> HoldForm[HoldForm[x]*y], Infinity]
Thank you for your reply. This really works with the multiplication term, but how can I keep also the order of addition.
You can try with a pattern replacement. For example
(1/2 y + 3/8 x == 2/5 z + w) /. coeff_?NumberQ*v__Symbol :> Inactive[Times][coeff, v]
