Live Unwrap

Live Unwrap is a really cool tool. It lets you pin vertices and move them to unwrap the mesh in real time. This way, you can adjust all the UVs very quickly without having to unwrap again and again or move them vertex by vertex.

In the UV/Image Editor, go to the UVs menu on the header and activate the Live Unwrap option. To pin the vertices you want to place in fixed positions, just press P. Keep in mind that you have to pin at least two vertices. After pinning those vertices, which can be the reference points or the corners of the mesh, just move some of them (pinned vertices will be marked in red) and you’ll see how all the UVs adjust to fit your moves. In this mode, move only the pinned vertices. If you move any other vertex, when you move a pinned one, the unpinned vertices will be reset; only pinned vertices will be fixed during the live unwrap.

When you’re done, you can unpin the pinned vertices by selecting them and pressing Alt + P. Then, make sure you deactivate Live Unwrap before further adjusting the UVs.