In an effort to condense the sheer volume of "zomg what trinket do I use" threads, Swizzle and I will keep an eye here for questions.
Fire & Frost:
416 Will of Unbinding > 403 Will of Unbinding > 410 Insignia > 410 Cunning > 397 Insignia > 397 VPLC> 390 Will of Unbinding > 397 Cunning > 391 Necromantic Focus > 384 Insignia > 384 Cunning > 384 VPLC > 359 DMC:V > 378 NMF > 378 Foul Gift of the Demon Lord
Arcane:
416 Will of Unbinding > 403 Will of Unbinding > Shard of Woe > 410 Insignia > 410 Cunning > > 390 Will of Unbinding > 397 Insignia > 397 VPLC > 397 Cunning > 384 Insignia > 384 Cunning > 384 VPLC > 378 Foul Gift of the Demon Lord
** Note: I've removed most 359/372 trinkets off the list as there's now easily obtainable trinkets that are superior **
Aside from this, ask any specific questions as to what is better for you.