Fixing noise after using Keylight on subject?

Hi, you could also try PremierPro "Ultra Key" instead of AE "Keylight". It worked well for me. It's noise free also faster than Keylight. Just set it to "Aggressive". 

I followed the tutorial from Surfaced Studios and he does a great job explaining how to do things step by step, but it's little stuff other than noise the edges will sometimes get really jagged and I'm at a of of how to fix simple stuff like that.  I'm not making Avengers here, but geez it should be able to look a lot better than what I am getting.

Also - since you can rarely pull a proper key with a single instance of keylight, you can add your mattes together and have a single layer as your fill.

Not quite - with the extra layer you have the ability to process the layer after the key - without effecting the matte

Under Keylight > Screen Matte category you have a setting called Replace method. When you get a noisy result, is it better to change this parameter to Source. Also you can contrast your matte to get better result in the same category using the Clip Black and Clup White parameters. Maybe it is not perfect but a better start point to clean the matte

This is probably due to Keylight's notoriously aggresive spill supressing. Try this: use "intermediate result" instead of "final result" and for the spill use Ae's "advanced spill supressor". If that doesn't cut it, I recommend NeatVideo noise removal plugin

Without any info or screenshots of your footage and settings this is difficult to tell, but feel free to experiment with the Remove Grain effect. Though, to be honest, it is more likely that you need to change procedures. Your footage may be shot the wrong way or you have overcranked your settings.

Mylenium