Is there any ibadah (such as salatul tasbeeh, fasting on day of arafat, etc) that can be done to be forgiven of a major sin and not just a minor sin?

1. In principle, it is necessary to make sincere Tawbah (repent) from major sins. In order for a major sin to be forgiven, one must sincerely repent (make Tawbah) by regretting committing the sin and making a firm conviction never to repeat the sin. If one is sincere, Allah is Tawwaab (most forgiving)
2. Rasulullah (Sallallaahu Alayhi Wasallam) said, 'There is no obedience of any creation in the disobedience of Allah. To trim the beard lesser than the span of a fist is not permissible. You should display good character before your parents and apply wisdom and diplomacy in keeping a Sunnah beard.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai
FATWA DEPT.