Channel 1: cold-DMing creators you already watch
Cold-DMing creators whose videos you genuinely watch is the highest-trust discovery channel because the pitch lands from a real viewer, not a stranger. The catch is volume: most established creators receive between ten and fifty unsolicited collaboration pitches a week and ignore most. The pitches that get a reply share three traits: they reference a specific recent video (not a generic compliment), they propose one concrete collab format (not an open-ended ask), and they include the pitcher's channel link upfront so the recipient can vet without asking. Cold DMs work best when the gap between the two channels is no more than three-times in subscriber count.
Channel 2: collaboration Discord servers
A dozen public Discord servers exist where YouTube creators post collab requests. The signal-to-noise ratio varies wildly: some servers are dominated by accounts at fewer than 100 subscribers looking for paid promotion, others are genuinely active with monthly active creators in the tens of thousands of subscribers. Discord works best for niche-specific collaborations because the larger servers usually segment channels by category (gaming, beauty, education, finance). The downside is throughput: a Discord pitch competes with dozens of others in the same daily channel scroll, and there is no persistent searchable listing surface.
Channel 3: replying to comment-thread asks
Creators sometimes pin a comment on their own video saying "looking for collab partners in [niche], reply here". Responding to one of these threads converts unusually well because the timing is explicit: the creator is asking for collaborators right now, and the reply lands in front of the creator's own moderation queue rather than a flooded DM inbox. The volume is small (one or two threads a week across the active YouTube creators in any one niche), so this channel works as a supplement to others, not a primary source.
Channel 4: a dedicated collaboration marketplace
A collaboration marketplace like CollabPals Collaborations collapses the first three channels into one search. Every listing on CollabPals is an explicit signal from a creator who wants to collaborate right now. Listings are filterable by collab format, subscriber tier, and trending engagement, so finding a well-matched partner takes minutes instead of weeks. The two main advantages over cold DMs are throughput (browsing dozens of open listings in one sitting) and intent (every poster is actively looking for partners, not deciding whether to respond to your unsolicited pitch).
Pick the right subscriber tier
The most successful collaborations on CollabPals pair creators within a two-to-three-times subscriber range on either side. A 5,000-subscriber creator pairs best with partners between roughly 2,000 and 15,000 subscribers. A 50,000-subscriber creator pairs best with partners between roughly 20,000 and 150,000. Beyond that ratio, one channel tends to deliver more than it receives, which makes the partnership less reciprocal and less likely to repeat. CollabPals exposes three tier-specific facet pages so you can browse only listings open to your range: small creators, mid-tier, and established creators.
Write the pitch that gets a reply
The pitches that convert best on CollabPals Collaborations follow a seven-line template: who you are in one sentence, your channel link, your subscriber count and primary niche, the specific collaboration format you are proposing, a concrete content concept (not an open-ended idea), the cross-promotion you will commit to, and a proposed publish window. Listing posters scan dozens of replies and pick the one that requires the least follow-up to evaluate. A pitch that arrives with all seven pieces already in place outperforms a pitch that opens with "hey are you down to collab" by an order of magnitude.