Once starting to understand the swing and getting continual lessons, you will start having a clearer idea on what the swing should look and feel. A fantastic way of ensuring you have great practice sessions is setting up a camera behind you. You can utilise a tripod and on different swings have the camera set up in front of you and on your backswing. The first time using the camera is after warming up with at least ten or so balls. You can then video your swing one from the front and one behind.
Evaluate the swing using ideally golf software. I personally use V1 Golf in which you can use the basic or premium version. This will enable you to draw lines on the screen and you can also compare your swing with that of a professionals. Your own golf education will start to really improve once evaluating Tour Pro's swings and identifying their similarities.
Once you've identified what to work on start implementing a swing drill that you know will address this issue. Do a number of practice swings as well utilising a mirror (if available) to see if you're applying the swing move correctly. Hit another 10 shots and do a review back on the camera. It's important to know quite quickly whether you are implementing the move correctly. Continue to put your swing on camera until the move is exactly what you want.
You can then go without the camera for some time while you are confident knowing that you're applying the move correctly. Another great tip is to do the swings really slowly. The slower you go, the easier it is to feel the new sensations in your body. Going too fast can be the greatest hindrance to improvement.
In completion to your session, put yourself on the camera one more time and confirm. When completing this style of practice session, you will start making great strides in your technique.
If you'd like any further help with applying the camera during practice session, just let me know.