30 STR and 20 Dex
Some example of meaningful affixes and their maximum values:
Prefixes:
2 class skill
2 class tab skill
90 mana (110 mana with 20 mana base on craft caster Ammy)
40 single res
20 all res
Suffixes:
30 STR
20 Dex
60 life
10 life rep
75 poison length reduction
10 FCR (for a total of 20 FCR from caster Ammy base stats)
How crafting works is that it takes the base stats of a craft and then you get up to 4 more affixes. A caster amulet as an example gets 10-20 mana, 5-10 FCR, 4-10 mana regen. Then you pick either 3 prefixes and 1 suffix or 2 prefixes and 2 suffixes or 1 prefix and 3 suffixes on top of the base stats of the craft.
Meaning if the Ammy have 2 skill and 20 FCR, it rolled with 1 prefix already (2 skill) and 1 suffix already (10 FCR). Meaning you have 2 affixes left to be used. Since you already have 1 prefix and 1 suffix, the remaining 2 affixes available can be either a prefix or a suffix, or 2 from either category.