A journal is prestigious because the papers it publishes have an allusion of quality, because they are published by a prestigious journal.
A prestigious journal publishes high-quality papers because it can attract high-quality authors and reviewers, because it is a prestigious journal.
A journal is prestigious because researchers choose to (try to) be published in it, because their articles will be widely read by other researchers, because it is a prestigious journal.
If you were trying to bootstrap a new journal, you'd have a tough time; unless you didn't care about its quality.
The bare minimum would be a staff who have the time and skill to sift through obviously junk papers and then know which reviewers to use for the legitimate papers. Your best bet would probably be to assemble a staff of well-regarded researchers in whatever field(s) you wanted the journal to cover.
You could (should?) start by going through freely published (open access) papers, collecting the most quality ones, then publishing them in your journal. That's most of the value of journals, as well - informing the subscribers of noteworthy research.
As Kernighan almost wrote:
Reviewing the paper is twice as hard as reading the paper in the first place. Therefore, if you have to be as clever as possible to read the paper, you are, by definition, not smart enough to review it.
[1] Although I can tell whether the code works, the quality of a paper is also about how well-written it is, whether the arguments are valid and supported by the data, and whether it provides something future research can be built on. A terrible paper that happens to contain code that works is useful for me, not so much for science in general.
You might even start with only yourself. And in 5 years if you want to distance yourself from your earlier, naïve efforts, then simply announce a name change.
Here's the ugly truth - it's hard to tell if most papers are "good", and there are many types of "good".
In my field, the main journal used to be "Journal of Computer Documentation". It spun off from "American Documentation" in the early 1960s. The JCD title changed in the 1970s to "Journal of Chemical Information and Computer Sciences" because "documentation" - a 1920s term - was considered already old-fashioned by the 1960s, and the title didn't capture the new focus on computers, and the underlying principles of information science.
It then became "Journal of Chemical Information and Modeling" in 2005 because the 1990s showed how to apply those information techniques to make predictive models.
Each name change is a form of distancing itself from its previous focus as part of a shift to a new focus.
Or is "distance oneself" not applicable for that situation?
Faculty of 1000 is the only thing I know of that's even close to this.
http://processalgebra.blogspot.com/2015/12/the-novelty-of-ar... lists a few more, including "Logical Methods in Computer Science published its first issue ten years ago and has become one of the favourite publication outlets for researchers working on logic in computer science, broadly construed."
I was just commenting about how to get around the "the journal isn't prestigious so no important research is published in it so it's not prestigious" problem.
You could create a newsletter that's useful to some, but if anyone would consider to publish their new research findings in your journal, then that would be bad for them since it wouldn't be considered anywhere equal to a "proper" publication (since you openly claim to accept non-novel findings as well) and would also prevent them from ever publishing it in any "better" journal since that would not be unpublished research any more.
In practice new good journals are generally started by (sub)communities who know each other and feel that [a topic of] their discipline is not adequately covered by the existing journals. This means that since day 1 they have (a) a source of good new papers that they will want to send there and not elsewhere - the whole reason for them founding the journal, (b) a pool of respected and knowledgeable editors/reviewers (the same community), and (c) initial interest of the community who would all read (and cite) the journal. Given that, the only missing part is recognition by various indexes and funding agencies, which will arrive within a few years (3-5?) if the new journal is well run, productive and gets appropriate citations outside of it.
But I'm commenting now more to point out that some journals do accept non-novel findings, like 'Journal of Negative Results in BioMedicine'.