I would also add that you need to know what the room is used for and remove anything that doesn't apply!
Also, we all need a junk drawer, just not one in every room.
To start with, put like with like and build from there. I'd start in the lounge, start at the door, work your way around clockwise with a laundry basket or large box. If it doesn't live in the lounge, you having already decided what the lounge is used for, then it goes in the basket/box.
Now sort the basket/box.
Charity shop Rubbish bin Other room in the house
There are no half-measures doing it this way so be warned It's very thorough!