The secret for me is that I don't draft, proofread, cross-reference, or revise.

For this particular case, these posts are bolstered by the fact that they are introductory posts, and thus have a lot more narrative 'time' to cover. We can freely yap about the entirety of the journey, our character's internal monologues with regards to the city and/or festival, and don't have to involve any other PCs in the yapper-y. So yeah, there's an acceptance that most of the post that is written wouldn't be addressed ICly by others.

Ultimately though, long posts are more a consequence of someone vibing rather than an objective, especially if you're not in an RP that has strict minimum words per post hijinks.