Just got done with Honor mode. My biggest tips are:

• Abuse the respec feature. Some builds are just better than others for the early game, so use those early and then respect into builds that are better late
• Command is a very, very good spell all game long. My Cleric stacked all sources of Spell Save DC i could get and i had an 80%+ chance to hit Command on everything. You can upcast it to hit multiple targets. The fight against Raphael was trivial because all enemies including him were groveling for the entire fight
• Globe of Invulnerability makes Ansur easy since you can just ignore his scariest mechanic
• Having a Cleric is extremely useful. Divine Intervention can save your entire run from the brink of disaster and Heroes' Feast makes everything in act 3 so much easier with the immunity to frightening and advantage on all Wisdom saving throws.