Traning without guidance

I've been playing for a couple of years and I would like your advise on how I can remember all the skills I've already learnt and not forget them when I learn a new skill.  For example I first learned a topspin against block.  More recently I've learnt to loop against backspin and receiving serves by top-spinning them in general.  For the last couple of weeks I've been struggling to finish mid-high balls with a fast topspin and i couldn't discover the reason until tonight when I was shadow-practicing in front of a mirror and i noticed my higher than required finish position.  How do I ensure that I don't repeat trivial mistakes like these and thus not waste time on remedying things I've already learnt?

Hi Abhiram,

This comes down to muscle memory.  It also comes down to analysing what is happening each time you make a mistake.  Try to work out whether it is your position, your stroke start or finish position or the not reading the type of ball that you are receiving.

Watching yourself in a mirror can be a useful tool.  You can also video yourself while playing which will be even more effective.  If you have a phone that takes a short video that is enough to see what you are doing.

If you are thinking your way through then you will get improvements faster.

By the way, you have done a great job to have all of those strokes at a competent level already.