Women in Prison will accept any craft materials at their pickup points in London (Stockwell), Woking and Manchester.
E.g. card-making materials (including old cards), pens, paint, colouring pencils, glitter, wool, pipe-cleaners, crafting paper and card, beads, buttons, etc.
February 2021: Women in Prison have been overwhelmed with donations in the London Area donations to Woking or Manchester may still be possible, please check their FAQ page: https://www.womeninprison.org.uk/contact
Also consider local primary schools, play groups and refugee centres.