I had a time when I wasn't improving a lot for quite a long time and couldn't find what I was doing wrong. Then I found out that the most time I was losing was during braking. You have to brake as late as possible but still being able to hit the apex...for example I was doing the mistake of not downshifting fast enough by breaking - this helps really a lot. Since then I got considerably faster but there is still practice to do for me - I probably don't have that much talent but I have fun and try to improve fine details. I don't have a smallest chance to get close to top drivers but also without talent but with enough hard work you can get more than above average driving level.