In Marvelous Designer, your patterns are your UVs. So if you want your UVs to be nice and orderly, make sure to space out your patterns before exporting your clothes.
If you select "Unified UV Coordinates" when exporting your clothes, all your textures will be scaled and rotated to the exact same angle/size etc. If you wish to export the clothes from Marvelous Designer exactly like you see them with textures you applied (and rotated, scaled, transformed), then make sure NOT to select this option!

From Marvelous Designer v6 and up, you have an edit UV tool which allows to see what your UV map will look like and change the size/scale of the UV map bounding box/borders around the UVs.