Generally the cap shrouds will be the tightest, followed by the forward lowers and finally the aft lowers. The objective with rig tuning is to pre-stretch the wire so you don''t have excessive flop when you load up the rig under sail. (i.e. leeward shrouds should remain under slight tension when you are close hauled in a good blow.)
I like to keep mine so that when I''m close hauled fifteen to twenty kts.to weather,the leeward shrouds are slightly loose.That way when I''m not under sail the mast is not being drivin down as much,easing stress.
The problem with that approach is shock loading of the wire during the gusts/lulls. Riggers I''ve discussed this with all seem to agree that shock loading is bad for the overall life of the rig and should be avoided.