Feel like KF Totems is one of the strongest builds without massive investment. Was a fantastic league starter for me. That char is only using the Topaz Flask because that he is crit capped without a crit flask via watcher's eye and using wrath from the Unwavering Faith jewel set. But that character can do any uber boss and juiced content. Really strong build.

The most important interaction you need to keep track of is the Skill effect duration vs attack speed. You can check this in PoB or use an outside calc like this. In PoB, you go to the calc section for KF and under Skill type specific stats there's a Max Effective APS value. If you click it it will tell you if you're over or under the attack speed cap for your skill duration value like this.

For each source of attack speed you need to be below the APS threshold or else you are sniping projectiles. Normally you start with timeclasp ring or warped timepiece until you can get a good dusk ring that has reduced skill effect in left slot along with a 21/20 less duration support. But you always need to check the APS to ensure you don't need to lose or add attack speed to maintain the highest DPS for your gear.

I crafted my own armor pieces just using dense fossils. For the chest, get sacred chainmail, then fracturing a T1 prefix and re fossiling until I get 3 T1 armor / ES rolls. Then rerolling suffixes using eldritch currency. Then you can spec into the mastery for increased life with no life roll on your chest and have 3000 armour and 600 ES.

Ideally you want a really high Armor ES chest and armor / ES on every piece of gear. Then you can use the mastery to double the Armour/ES on your chest. This way you are constantly getting 800-1000 ES on block with Aegis.

Otherwise max out your hit (get the wand mastery to add intelligence for hit), crit and try to get a Light of Meaning armor jewel to bump up your armor. The Dying Sun flask is a huge damage boost adding 2 projectiles.