Either
-5x Night Mothers Gaze/Hundings: Craft-able and offers good damage in all scenarios. Night Mothers is better than Hundings usually but don't run NMG if someone else is, use Hundings/TBS instead.
-5x Twice Born Star: When running trials with good Warhorn uptime TBS has the potential to perform better than Hundings. Use the Shadow as your second mundus. Craft-able aswell.
-5x Red Mountain: This set's 5pc hits so damn hard, even if it is flame damage.

-2x Velidreth/Kra'gh: Veli is better for mobile targets and in trials, Kra'gh is super good solo.
Either:
5x Viper: Just like Red Mountain this just does heaps of damage when it procs, run this on weapons as your Bow procs Red Mountain but not Viper far as I am aware (Go Maelstrom bow if you can get one otherwise just any sharpened one will do, I use a Red Mountain bow)
Or
3x Vicious Ophidian/Alkosh Jewelry: 5% extra damage in trials and dungeons plus extra crit, can't go wrong with that.
2x Maelstrom Dual Wield: Provides an extra 180 weapon damage and allows for empowered Dawnbreakers or Lacerates.
1x Maelstrom Bow: The empowered Volley and 180 weapon damage make this the winner. Masters bow is also quite good.

If you're still leveling, just use 5x Hundings 4-3x Night Mothers and any any old jewelry you find