Don't just dump bulky items by the bins - the regular bin lorries can't take them. Arrange for a special uplift. It only costs £5.
Or you can call the national reuse phone line to arrange a free uplift: 0800 0665 820
Or you can donate online(external link). Items will be collected by a local organisation and reused.
If you live in a tenemental area and use the communal bins, it is often confusing. What goes in which bin? The Council have a handy poster to make it all clear. You could download it, print it out and stick it up in your flat or stair.