You can set yourself assignments.
Such as: force yourself to only find one-coloured objects, or align things (optically) that only represent one certain colour.
Or you try to work with lights, and if it only be desk lamps you use on a still object that you light this way and that and another way and so on. (If it's only desk lamps you have, make sure your camera is on a tripod, though).
Or you try out assignments such as "fill the frame", or "motion", or "frozen movement", "shadows", "reversed lens macro" (in case you don't have a dedicated macro lens but want - for once - to get really, really close to your objects), repetition, leading lines, all such compositional specialities can become an assignment...