Practice - this is a must.

The text and inscription--although the "body" is different, the "qi" must be consistent...the "seal" must be good and carved by yourself...

It's better to read more. Practicing calligraphy alone is not complete - read books on the history of calligraphy, reviews of calligraphy aesthetics and other books - and also read books on common sense in calligraphy - this is a process of accumulation over many years - --The so-called cultivation of the art of calligraphy--of course it is not just the cultivation of calligraphy--

It depends on your talent, talent, understanding, learning, willpower, time devoted to work, concentration, method, vision, mind, direction... …