This post is intended for Tumblr, and as a general info thing for Tumblrites, but I want to keep it here as well, and typing it up here first means I won't have to go through the tedium of find-and-replacing all the curly quotes and apostrophes or manually entering italics tags after the fact (as opposed to as I go). I mean, yes, technically, I can keep the curly quotes and apostrophes, but a long time ago they were showing up as unreadable symbols in my inbox-at-the-time, so now I have an Unreasonable Grudge against them. Edit: Tumblr link /Edit
Anyway, essay time!
There's a number of technological and cultural shifts Tumblr users would have to make when switching to Dreamwidth; image hosting (and the lack thereof) is probably the biggest technological switch, but the one I anticipate giving people the most trouble is tagging.
On Tumblr, you can add pretty much whatever you want to the tags, in any order you want; there is no limit to them, and they're essentially used as a secondary comment system.
Not so for Dreamwidth! Dreamwidth has a hard limit on the number of tags any journal or community can register; it's 1,000 for free users, 1,500 for basic paid accounts, and 2,000 for premium paid accounts, and they're basically entirely for organizational purposes. One of the ways that Dreamwidth's code reflects this is that it lists tags alphabetically in posts, not in the order that they were written or added. If you want to include a stream of consciousness in your tags and have them make sense, your best bet is to find a way to make them alphabetical. There's also a hard limit of 40 characters per tag for everyone, regardless of account type (paid or free).
There are other organizational options, Memories chief among them, but it's not really possible to opt out of tags being organizational and switch them to being communication. So what, if anything, can you do instead?
So there you have it. Dreamwidth may not have "talking in the tags" the way Tumblr does, but it does have some other forms of communication that you can still have fun with.
(Side note: You might also be able to do fun stuff similar to the "Currents" options with the Age Restriction section, but I haven't tried that one, and honestly it might be heavily dependent on the registered age of who's viewing it. If you're making a fun joke that you don't want people to miss out on, maybe stick to the other options.)