Many people bank and can't feel it. Some bank on left turns but not right, or vice versa. It's hard to change something if you are unaware of it. Here are some drills which will help you feel when you are banking and when you are not.
1. Stick your poles together. Hold them out in front of you with both hands, and keep them more or less horizontal. When you are moving across the slope, keep them "level" with the pitch of the slope, which means the uphill hand will be higher than the downhill hand. When you are moving down the slope, keep them level with the parking lot, which is also level with the snow under you. In other words, keep the poles "level" with the slope angle as it changes due to your direction of travel. Holding the poles that way should keep your shoulders level with your hands and poles. Of course you can cheat by banking as usual with your body and shoulders while contorting those poles so they are "level," so try not to do that. Keep arms and hands and shoulders all normally aligned with each other.
2. Hold poles firmly in both hands, vertically pointing down. Drag the baskets against the snow. You won't be planting the poles, you'll be keeping their baskets dragging the whole run, and keeping them vertical. This accomplishes the same thing as the horizontal poles; it keeps your hands, and hopefully shoulders, level to the slope. You can cheat by bending one elbow more than the other, so don't. Keep arms and hands and shoulders all normally aligned with each other.
There are a bunch more drills that can help you keep the body from banking, so you can experience the feeling and work on embedding it into your skiing. The general pattern that bankers do is a quick pivot at the top of the turn to get the skis facing in the other direction, then then lean uphill, in towards the hill, with their whole body as the skis travel towards the side of the slope. The leaning-in (banking) helps with tipping the skis. Sometimes attacking the leaning-in directly is not what needs to be changed first. Maybe in your case working on turn entries would be better. It's hard to say without being on snow with you.
Here's a fun one. You know how on very cold days your nose tends to drip? It should drip down onto the outside ski as the skis travel across the trail. If nose drip is aligned properly with the shovel of the outside ski, usually the uphill/inside shoulder and arm and hand are higher than the downhilll/outside equivalents, and you're facing downhill enough for the uphill/inside half to be ahead of the downhill/outside half of your body as it should be. Drip properly and you're good to go.
Edited by LiquidFeet - 9/23/15 at 11:48am