I've found that just having vague ideas in mind is enough, external circumstances will dictate the best order to brew them. Having external constraints can help, too.
So, in my case, the original motivation was that my wife and I wanted to make mead. After reading up a bit, I wanted to ferment something else first to get a handle on the process (sanitation practice, mostly) since mead doesn't hide flaws too well. So that's why we started on beer.
First beer needed to be simple, fast, and foolproof, so we did an ordinary bitter. Then started the mead. Next, wanted to do another beer, but needed it to be something that my wife likes, so that suggested that a stout would be strategic. We then started a cider, which required acquiring another carboy. I'd now generated enough goodwill to do a Kolsch, one of my favorite styles.
Next up I committed to doing a strawberry blonde ale as a "her" beer. For myself, I wanted to go with an Altbier reusing the yeast from the Kolsch. When I realized that strawberries weren't going to be in peak season for a bit longer, that was a good sign to swap the order on those two. This had the side benefit of a shorter storage period for the washed yeast from the Kolsch...
I have a few future ideas, but I'm not sweating the decision making too much. I find that when an empty carboy is visible on the horizon, I'll know what I need to make next. Trying not to let my overthinking problems take over my brewing life...