I have a doubt related to using the word "up" after a verb. I have heard people using it when they say "shinning up" for example... Is it a personal choice or there exists rules to use it?
That sounds like a literal meaning- the direction. It can often imply completeness- cut up is stronger than just cut. It is also quite often an empty preposition just tagged onto a verb. Try searching for 'up' here to see our list of verbs using it: http://www.usingenglish.com/reference/phrasal-verbs/