This bag about to leave your house might be better off as a big plastic garbage rather than a paper grocery bag.
Go through your extra blankets, pillows, and sheets. Put the ones you haven't used in the last year in the bag.
Now check the winter coats, scarves, gloves, sweaters, rainboots, etc. Add any of those you haven't used in the last year.
Now take the bag down to the homeless shelter or another local charity.