I do this professionally (stage properties) this is what you need to do:
Kitchen: Clear all surfaces, windowsill, remove bookshelf, remove wall decor/photos etc. Leave a few small counter accessories out but store everything else, leave 1 or 2 plants on window. Install plain white subway tile on backsplash. Put blind up (unless the view is terrible).
Living room: Declutter, remove all artwork, but keep 1 large to go above sofa and maybe 1 or 2 others for opposite wall. Keep sofa, accent chair, large rug, lamps, side tables. Remove flowery tablecloth replace with white. Remove writing desk and chair. Repair nail holes and paint wall neutral colour.
Main Bedroom: Keep bed, accent chairs, curtains, yellow rug. Remove everything else. Put white bedding on the bed and use a few accent pillows. Change lampshade to plain one.
Kids Bedroom: Keep beds, curtains, blue rug, declutter art, declutter bookshelf, remove chair, remove piles of art, remove kids name banners.
Bathroom: Store away all towels, clutter, toliettries, paint cabinets and bath.
I think your flat looks great, but trust me this is not what 99% of buyers want. You are moving anyway, so just pack away the stuff now, you will get a better price and be more organised for when you move.
Good luck.