When would you suggest start doing collaborations?

[HiEnergy]

I can't see why channel size/number of videos/views/view hours/subscribers/<insert random metric> should be a limiting factor for working together with others.
E.g. on my channel I have a "featured" channel of another composer, who in return "features" my channel. I'd already count that as a form of collaboration though the most basic one.
Nobody stops you from working together with other Youtubers. Go ahead and do it!

 

[GameVestment]

I can't see why channel size/number of videos/views/view hours/subscribers/<insert random metric> should be a limiting factor for working together with others.
E.g. on my channel I have a "featured" channel of another composer, who in return "features" my channel. I'd already count that as a form of collaboration though the most basic one.
Nobody stops you from working together with other Youtubers. Go ahead and do it!

Great advice! I'll totally take it into account! The featuring channel is a great idea I didn't think about before. Hopefully I'll find someone in the future.