A variety of methods and devices providing for the angular and lateral adjustment of some types window shades is disclosed. As window openings often reveal a variety of geometric irregularities, several window covering systems, particularly roller type window shades, exhibit poor geometric fit within window openings. The present invention provides for variety of angular and lateral adjustments of shades in order to correct various defects of fit of those shades within window openings by controlling external and internal gaps relevant to the rolling process of the shade.One method disclosed, referred to as Procedure A, involves the reversal of the roller actuating mechanism from one side of the roller to the opposite end in a Hunter Douglas Silhouette shade. This reversal alters system of forces and moments acting on the shade assembly and brings desirable modifications in both lateral and angular position of the shade.Another method disclosed, referred to as Procedure B, deals with adjusting the effective diameter of one end or the other of a shade roller. This method allows to effectively control the magnitude of the internal gaps relevant to the rolling process. If it is applicable to various types of roller shades. Several different mechanisms and/or devices allowing to control internal gaps through adjustment of the effective diameters of roller ends, are disclosed.A third method, referred to as Procedure C, discloses various devices able to torsionally adjust main housing of the shade in order to control the magnitude of the external gaps relevant to the rolling process. This procedure can be performed by either altering position of relevant end plates or relevant mounting brackets, in their relation to the window lintel. Any of the methods or mechanisms disclosed may be combined in many ways as needed or desired for optimum effect.