For measured improvement how many times a week should you actually practice?

Ultimately, it's all down to how you practice not how much you practice. For example, hitting 60 balls over a period of an hour or two with specific practice swings and drills will benefit your golf tenfold over smashing 240 balls with no specific practice thought or goal. But I would say personally if you could set aside 5 to 10 hours a week of proper practice, that is plenty.

How can people find out what they should specifically be practising that will benefit them the most?

Skills testing and taking data from on course rounds. In order to seek out your weaknesses, you must place yourself in tournament pressure scenarios to get real-life feelings. Then you need to accurately record the data, then analyse it. Break it down into sections. The long game: off the tee, long iron approach play, mid-iron and wedge game. Short game: pitching, bunker, chipping, putting.

Then work on the worst areas.

How can using Toptracer improve my practice and results on the course?

Toptracer is one of the most effective practice tools I've seen in the game since I've started playing. Toptracer is perfect for dialling in distance control, learning about what club is your strongest and weakest. But also creating pressure scenarios with approach challenges and virtual golf I couldn't think of a better way to spend a rainy day then playing virtual golf undercover around some of the best courses in the world!

Before playing, what should I practice/include in my warm-up?

This is a great one and again a very personal question as it's different from everyone. But the routine should always be the same and the amount of time spent should never change.
Personally what I would practice before I go out is:

Putting- find the speed of the greens and get used to holding 6 footers and in to build confidence.
Chipping/bunker: get used to how the ball reacts on the green and also the softness of the ground/sand.

Finally, always finish with hitting shots. This is so your body is fully warmed up ready to hit that first tee shot.

What can I expect from a lesson with you?

To learn something about your technique, to gain an understanding of how to improve your golf and finally experience learning in a relaxed and supportive environment!