Diffraction analysis of single-crystal data in two dimensions is very good for eliminating candidate structures, and for suggesting possible indexings depending on your confidence in the measurements themselves.
Related references
P. Fraundorf (1981) "Stereo analysis of single crystal electron diffraction data", Ultramicroscopy 6, 227-236.
P. Fraundorf (1981) "Stereo analysis of electron diffraction patterns from knowns", Ultramicroscopy 7, 203-206.
RW Collins, P Sheehan, M Higley, P Fraundorf (2012) "Fast Periodicity-analysis with '4spots' and ImageJ", Microscopy and Microanalysis 18:S02, 1256-1257.