@Crystal Mtn, thanks for those answers. I'll offer some thoughts. Hopefully others will chime in too.
1. You've had enough experience to embed your current style deeply into muscle memory. To learn to make smooth turns on all kinds of terrain, not just on early morning groomers but on cut-up crud and bumps and fresh powder, you'll probably need to change your current "style." It's hard work to change deeply embedded habits, but a great enterprise to take on. To make those changes stick, one needs to concentrate on making new movements happen, every turn, until those new movements get strongly enough embedded that they can happen unconsciously. Determination and persistence is called for. Working on one's skiing can be fun, and it's definitely worth it!
2. I envy you that 12-25%. But even those numbers leave 75-88% of your time dedicated to skiing groomers. That's where you'll need to do your deliberate practice to learn and embed new habits, which will make skiing variable conditions fun.
3. Let's assume your boots fit ok, giving you good control over those skis. What skis are you on???
4. How you start your turns is the key to success. You need to know how you start them, what works, and what doesn't. Many people who have been skiing without lessons for a decent amount of time don't know how they are making their turns happen, so you have lots of company there. Start your turns well and the rest of the turn falls into shape more easily. How to do that is a whole conversation in itself.
5. If you handle morning groomers fine but not the afternoon cut-up stuff, and if baby bumps give you problems, you are probably making turns that rely on rotating the skis around manually using the muscle power of your legs. Ot you might be braking at the end of the last turn and then rotating your whole body to drag the skis around, which may cause your skis to start the turn without being parallel; that's not good in any kind of grippy snow. You may be cutting off the top of your turns with a quick pivot, which makes it hard for your skis to get a grip. You may be leaning your whole body sideways or uphill to get your skis on edge, which lessens the ability of your outside ski to do its work. You may be a little back seat, which keeps the front half of the ski from being able to shape your turn. Some combination of those is quite possible. I'm guessing here, of course.
This is a list of some of the most common issues of many skiers. I'd suggest a lesson to sort out what's really going on. Or have someone shoot video of you and post here, if you can handle anonymous people telling you what's wrong with your skiing as they give suggestions for improvement. Doing that can be quite useful, but it can also be a painful enterprise. Or go online and watch instructional videos; there are lots available for free.
I'd choose a lesson, but then I'm an instructor so you could have predicted that answer. Best of luck on getting that flow going!
Edited by LiquidFeet - 12/29/15 at 8:55pm