Well, you could use Stone of Jordan rings if you wished to have a much larger mana pool, or simply use Bul Kathos' Rings if Life were something much more important to you. Both offer a small boost in your Bonespear damage and Clay Golem's longevity and Slow effect, as well as a small increase in Decrepify length.
But at present, how are your resistances to all forms of elemental damage, namely lightning and fire? If they are lacking, rare rings commonly offer such bonuses that ought to bring your resistances either up to full or very close to it. Also, do you plan on fighting people that use Cold elemental attacks? If you don't already have an item granting Cannot be Frozen, then use a Ravenfrost ring in order to not be crushed by the freezing effect.