Protect it with one rule
The corner will quietly die if it becomes the place where the laundry basket lands, the ironing waits, or the children's school bags pile up. Give it a single rule and say it out loud to whoever you live with: nothing that belongs to a task is allowed to live here. In our house, the rule is that the chair holds people and blankets, nothing else, and it has survived three winters of being tested by a teenager with a rucksack.
If the corner is in a shared room, it helps to agree what it is for rather than who it is for. A seat the family understands as "the quiet chair" gets respected in a way that "Mum's chair" rarely does, and anyone who needs twenty minutes away from the noise can claim it.
What if the only room I have is shared with everyone?
Define the corner with the floor and the light rather than with walls. A rug edge, a lamp and a chair angled slightly away from the television are enough to read as a separate zone, even three metres from the sofa. If the room is genuinely in constant use, consider timing instead of territory: the corner belongs to whoever wants it after the children are in bed, which costs nothing and still gives you somewhere to go.
Can I make a corner cosy without buying anything new?
Almost certainly, yes. Move a lamp from a room you rarely sit in, borrow a throw from a spare bed, reposition an existing armchair so it faces into the room, and swap one cold-toned bulb for a warm one. The two changes that do the most work — low, warm light and a surface for a cup — are nearly always achievable with things you already own, rearranged.
