And in my experience, those people are anywhere from a little wrong, to completely wrong.
Here's one thing that may help you understand a little better (setting aside flavor percentages for a moment).
Usually fruits play well as a SnV. Unless they have alcohol in the flavoring. Then, depending on how much alcohol is in the flavoring, you may need to wait anywhere from a minimum of 12-24 hrs for the alcohol to dissipate, or in some cases up to 3-4 days for it to clear. But alcohol is only one factor.
For some flavors, they need a chance to homogenize within the VG that it's been mixed into.
This varies both by flavor, and by brand. Some of those flavors take anywhere from a week or two, to a month, and in certain cases, even up to 6-8 weeks!! So there's a second factor.
Next up that also plays a part is, are you mixing for MTL (usually a 50/50 mix, but sometimes 60/40) or for a DL (RTA/RDA) setup? The latter style of vaping has a very different type of wicking, and allows a much thicker liquid to flow easier. So folks typically prefer higher VG liquids. Given that there's more VG for the flavoring to have to meld with, it takes longer to do so, than it would if it was a 50/50 mix (because PG mixes with flavor faster than VG does!) So there's a third factor.
Given you say
Leads me to believe that you're using a DL setup, and that you're using at least 70vg (or higher) since you mention clouds and no flavor.
It also leads me to believe that you are in need of steeping your liquids longer (for starters) to see whether or not:
- you're just not giving the flavor enough time to permeate the VG
- or, you need a little more flavor.
Since you haven't mentioned any kind of chemical note, I don't think (at least at the moment) that you're going too high on percentages. But then, you've got other issues to deal with first in my opinion.
Good luck, and I hope this helps