1. How many Variables you have? Just one, More than one or Many.
2.What is your statistical objective? Describe, Identify/Classify, Compare/Test, Predict or Explian.
3.What Scales of Measurements do the variables use?
4. Are there dependent and independent variables?
5. Are the samples are auto corrected by location (1D,2D,3D) or Time/Sequence (1D)?
Once have answer for the above questions check the follow chart which is attached below