I remember one particular trip when I absolutely had it sussed! 2 pairs of trousers, 1 skirt,mid length, slightly floaty (I.e. not tailored/fitted), a shirt type top that matched the skirt from the same range, matching fabric, which could be worn with either pair of trousers or of course it's skirt partner. A couple of other tops that could be interchanged with both pairs of trousers and the skirt.
Blazer for over during the day, passions for evening.
All based on navy, another blue and white.
Accessories might be the thing, earrings, necklaces, scarves etc, take up very little space and can have quite an effect on an outfit.