on rings you just need to decide whether you wanna avoid lvl 96req stats such as 6ml or not.
if yes, lvl 80-83 is just fine. if you want them to roll 6ml too, use a 89+ char
detailed guide here:
https://forums.d2jsp.org/topic.php?t=30598890for amulets its lvl 93 to achiece the chance of +2skills on all amulet bases