I vape 80%Vg/20% a combo of flavoring and distilled water. That 20% could be 3% flavor, and 17% distilled water, for example.
The key for me very early on was to make sure VG heavy juice will wick properly in any atomizer be it a tank, carto, ... whatever we use. I am PG sensitive so Ive been mixing VG a long time now and at 80%vg/20% everything else you should never have wicking issues.
Frankly Ive added as much as 20% DW to plain vg just to see if I could and it was just fine.
Hope this helps.
Edit: Are you going to cut your VG with water before making juice? I suggest to always leave your VG whole. Dont cut it with water. Add your DW when you mix juices.