I have a campaign that's doing well and scaling nicely - I'd like to setup a lookalike audience but am a bit confused on how it's done. Below you can see that when I click "Source", I get a few options from which to generate from, but none of them are my pixel. My pixel has >100 events logged, but being that it's a 2-step offer, it doesn't quite have 100 unique users logged. I'm assuming the option will appear once I hit a true 100.

A few questions:
-What are best practices to follow insofar as deciding what % lookalike to go with?
-Thus far I've done some manual optimization - will this lookalike audience be larger than my manually optimized demographic? Or if I'm including my manual optimizations will it be a much smaller albeit more profitable segment?
Thanks!
I now have >100 users converting but still don't see an option to create a lookalike seeded from my pixel - does anybody have ideas?
Go to Pixels, not Audiences. Open your conversion pixel and you will see a button to create a similar audience.
Hard to answer your question without knowing some budget & metrics on what you're running but generally you want 3-10,000 sales for a targeted lookalike audience on the conversion.
I'm running BH and just wanted to see if I could increase ROI from where it already is. That said, 3-10K sales is out of the question. Think it'd be a lost cause?