The easiest way for me to order fractions is by decimal.
Ex: 1/2, 15/5/, 1/4
So you have to turn them into decimal form. Ex: 0.5, 3, 0.25
There are to ways to order them(greatest to least or least to greatest)
Greatest to least is 2, 0.5, 0.25 because you are ordering them to the greater numbers. For least to greatest you would just put the opposite.
Hope it helps :]