Multi Point Alignment
More Examples here
These images show how multi-point alignment improves even when you dont use the best images.
In Image 1 the alignmentpoints can be seen. Setting these points is as simple as a single-alignmentpoint (click with the mouse). The window to the right of this image is the multi-alignment window. It has several options like estimating the best alignment-positions, saving/loading preset alignmentpoints etc.
Image 2 shows the outcome of a single alignment using alignmentpoint 1 and image 3 shows the result from multi-alignment processing.
Notice that for instance near alignmentpoint 3 (crater Erathosthenes) the quality of the inner-crater details is a lot more defined.