While it is not essential, it is helpful to check these tilts out in front of a full length mirror. The differences are quite subtle and if you can see them, you can get a picture of the structure you want to feel. A mirror and a wall are the best training aides when you are working on golf posture.
The first tilt is in the knees. From a standing position, bend your knees and drop your body weight straight down. Look down and notice that you can barely see your toes. Now check out the small of your back and notice how it has curved to keep you in balance. For many beginners, this feels like the natural way to set up to hit a golf ball. A slight bend at the waist seems to ease the tension. Over the years, this set up left me with a chronically sore back and a severely weakened hip. The martial art training I later began taught me about developing proper postures so that quick movements would have solid structural support. I was able to rebuild my core muscle groups and give my golf swing a new life, without surgery.
From the knees forward position, raise your knees and shift your weight to your heels like you are going to sit down in a chair. To stay in balance you will notice that you have to raise your arms and straighten your lower back. This action pushes your backside out and now you can see your toes. This is the starting point you want for building a good golf swing. Tilt the knees forward and back several times so you have the feel of the correct structure. I have read articles touting the curve in the back and it makes me cringe. If you want to do that, I recommend Tai Chi for your rehab.
The second tilt is in the hip (right for right-handed). From that good starting point you were just in with a good knee bend, shift your weight slightly to your right foot as you tilt your hip straight back, keeping your knee bend the same. Shift the hip forward and back several times to get the feel of the correct hip movement. Here is where you can test the feel of some real swing killers. Try shifting the hip to the right creating a slight swaying motion. Yes, you can hit a ball this way and may be doing so without knowing it. If so, you are probably looking for distance in your shots and have some lower back pain. Try lifting the hip and straightening the right leg. This is a very common mistake, I know it well. When you are wondering how you could hit the ball so far off line, this is a good place to look. If you are fairly rigid in your torso, as I was, getting your hips loose enough to feel this could take some work. Dancing is a good place to start and the 18 Movement Martial Golf Form is great way to bring it home.
The third tilt is in the shoulders. Get into your usual address position. If you can roll your shoulders up and around to the back thereby straightening the upper spine and neck, then you started in a slumped posture and you should work on correcting it. Having the shoulders rolled forward puts tension in the neck and back muscles and makes the shoulder turn around the spine much more difficult. My martial art instructor calls it the "troll" posture. If your shoulders are already back and relaxed, I'm sure you are enjoying a good shoulder turn.
There are so many factors that go into a good golf posture. Do everything you can to get set up correctly and you will greatly increase the odds of a successful golf swing. And if you do hit a bad shot, instead of swearing, just say "TILT".