After the Latimer Road mapping party I’ve been adding the blocks of flats in the White City estate. I haven’t managed to set up plugins yet in JOSM so I’ve been tracing over the Yahoo pictures in Potlatch. I’ve found I can trace over the outline at roof level in the photographs (although this is not as simple with pitched roofs) and then move it to where you can see the bottom of the building, remembering that you have to select the way itself intead of the highlight roun it. The ‘use thin lines at all levels’ option is useful here but the outlines still don’t seem as crisp as I’d like. Practice makes perfect I suppose.