Here is what I found working for me. I am just making trials but the order of procedure is really time saver.
A.Import the file to meshmixer.
B.Delete free floating parts.
C.Check for Errors (Manifold errors, holes...)
D. Repair all Errors
E. Translate to origin
G. Translate again to origin
H. Scale to fit
I. Make Hollow
J. Generate support
K. Decide on infill percent, generate raft