Plan a Weekend Declutter Session for One Room

The spare room has become a dumping ground and thinking about it is worse than doing it. This splits the clear-out across Saturday and Sunday, gives you a simple keep, donate, bin or unsure system, and puts a realistic time estimate on the whole thing so it does not eat your whole weekend.

Help me plan a weekend decluttering session for [one room in my home, for example the spare bedroom or the garage]. Split the work sensibly across Saturday and Sunday, give me a simple keep, donate, bin or unsure sorting system to use as I go, and put a realistic time estimate on tackling a room this size. Keep the plan short enough that I do not need to re-read it halfway through.