Vinegar is effective, but rather than use newspaper, which gets messy, use one of these microfibre cleaning cloths which are now available and use it barely damp from the vinegar water solution. It's better if you wipe the glass first with one of these cloths and use a second one to dry the glass. And definitely don't clean your windows on a sunny day.
Use one of those things the window cleaner uses - sorry don't know what it is called, the thing with the handle and T shaped with rubber going along the edge. Get some washing up liquid on a wet sponge, wash all over the window so it is sudsy, and then just pull down with the window thingy, top to bottom, wipe off at the bottom where it is wet, and bob's your uncle. No more smears, no more rags, no more vinegar. Brilliant. And don't do it when the sun is shining in the window.