My personal ratio is driven more by circumstance than design -- for the past few years (modulo covid) I take a "ski week" of lessons at Taos (6 mornings) and no others, out of a total of 20 to 30 days. (So 1/3 to 1/5).
Skiing with a group of good skiers (i.e. other Ski Talkers) makes a huge difference. Not only can you see what they are doing, it also resets your expectations of what is normal.
When I stopped and thought about the big group we had competently skiing double blacks at Aspen during the Gathering, I was amazed. Many of them are also doing the Taos ski week plus chase-better-skier mix, and many of them were intermediate skiers beginning to ski easy bumps when I met them not all that many years ago.
Pay dirt.