YSK: When making posts on Lemmy/Kbin always put at the end some hashtags related to your post topic.
So users from Mastodon and Pixelfed can interact with your post without even need to use their Lemmy/Kbin account or learn about "how to use the ActivityPub".
This also helps to have more content avaliable across the Fediverse due to better discoverability.
Honestly think this is a bad idea. The platforms can talk to each other, sure, but Lemmy/Kbin just doesn’t translate to other services like Pixefed and Mastodon do. They’re just too different!