Tempest shield + life leech

I'd say support gems with no extra cost multiplier (Mana Leech, Iron Will, Blind and Reduced Mana) work best with Tempest Shield since you don't really want to increase that reservation.

Think Knockback would be worth a link?

does curse on hit work with TS?

I use blind, and i used to use iron will but its not worth it on my witch

TS lightning damage is a very high average at level 20, not low end and high end like other lightning skills, i see herald of ice works well with it and it has an 8% crit chance which when using the three dragons unique freezes enemies making it a very good defensive choice for high block high crit builds that use the helm, too bad my incinerator has no extra crit ><

curse on hit works fine with it. Albeit imho a bit too late, since often you kill mobs before they hit you.