At a bare minimum, a Cast On Critical Strike setup will require three gems: an attack, Cast On Critical Strike itself, and a spell to be triggered. This generally leaves at most three other supports that may be linked. If possible, the supports should both increase the number of times Cast On Critical Strike triggers, and increase the effectiveness of the triggered spells. Note that Cast On Critical Strike cannot trigger more than once per frame, so staggered hits (e.g. multiple projectiles) are preferred to simultaneous hits (e.g. most area of effect damage) which will only proc at most once per attack.

Since "double-dipping" on support gems is key to an effective Cast On Critical Strike setup, having a 5- or 6-link is more important than it is for most builds. Unlike conventional attack builds, attack damage is not necessary on passives or gear, though it can be helpful in situations where the linked spells are less effective. Attack speed and critical strike chance are the two essential statistics.

Accuracy is a desirable stat, as one cannot crit what they cannot actually hit. However, the loss of the critical strike stat granted from gem quality means this is no longer a top-tier supporting gem choice. Losing the critical strike chance affects not only the minion gem in the link; as mentioned minions have poor critical strike capabilities, and were only the minion affected there would be no noticable difference after patch 2.0.0. Of course, this is not the case, as the critical strike chance also affects the attack you are using to proc CoC (the 'trigger' spell), and any other spells to be cast on critical strike (the 'triggered' spells) in the link. This essentially results in less CoC procs overall, less damage from your trigger spell, and less critical hits from your triggered spells as well. This triple-whammy means that Additional Accuracy Support is no longer the top-tier option that it once was, with or without an attached minion and minion-buffing support gems. When considering only the minion, and ignoring any of the triggering/triggered spells & CoC proc rate, the golem/minion is likely perform better with a Faster Attacks Support instead of Additional Accuracy Support; minions will miss more, but making far more attacks per measurement of time. No longer recommended in a CoC link since patch 2.0.0 except to fill in accuracy you desperately need due to poor passive tree and/or gear options.