My decision is easy.
I have a build list of what is needed for my collection. I have all the decals that can be bought for it. And I have all the kits that are needed for it. The only supply I don't have all that I need of right now is the supply of weapons. It is possible to have to skip to another aircraft because I ran out of Sparrows or 500 pounders or something,,,because I didn't buy all of each type of weapons sets that I will need in the long run. (I only have 36 sets)
If there is any hesitation in choosing a kit (very unlikely, I like all the aircraft), I just reach for another Skyhawk. Sometime while working on that, another markings scheme will come to mind, maybe based on a trim color on the kit I am doing. Then I pull that other kit down. I stop starting kits when I have 4 or 5 going, I don't like to do more than that at one time.
The list lets me just go in order if I might ever get stuck on what to start. But, that didn't happen to me before I made the list up, so I don't see it happening today. Another thing that might happen is that I might notice that I have VF-11, VA-12, VF-14, VA-15 done, so I would just start on VF-13's and VA-16's models, just to get a sub-set finished.
Rex