Here is my fairly seamless warlock rotation that has very little downtime and handles 2 mobs pretty easily if it happens. This utilizes demonology spec for felguard as well as points in affli for drain soul/drain life spam. It resummons the felguard on a timer to heal his HP/mana. Alternatively you can add health funnel to the heal pet option. I would talent for health funnel if going this route. Feel free to use whatever keybinds you want for the spells, this is just how I set them. Attaching image and xml file, but I’ll type it all out for the sake of being thorough.
Download soulsort addon for managing soul shards
**Misc Settings: Run to loot: 2500, wasn’t having enough time to loot