#letsdoit is for those projects that you want to get done. You can use it to post the project itself, or as a way to ask for feedback, assistance, accomplishments, etc.
Thing about this tag especially is that I would use it for stuff that you're passionate about, or are greatly interested in getting started/finished or want feedback on, especially without cluttering other tags.
I dunno, we'll see how it goes and get a feel for it over time
I'm working on a comic. I can post some stuff but it's slow going. I don't know what I'm doing. I need a couple hours to do things first