Use Tor for everything. Search for "disposable email", find a service that you can use in Tor. Sign up through Tor using that disposable email address for any service that you want to post to. Be aware that some services try to deny access to Tor and/or disposable email addresses. Try a different service or a different disposable email provider if you encounter that.
You should define your threat model. Longer essays can probably be deanonymized with stylometry. The above will probably work fine up to maybe the NSA taking an interest in the origins of the essay. You can probably post something to the Fediverse and reputation-wash it to a larger audience by saying "look at this link that i have no affiliation with", but it's more likely that someone would figure out that it's you. You can use the Tor method to post on Reddit, but many subreddits will have automods that delete posts from new/low karma users.
Thank you 😀 It was good working together