you know you've got nothing to offer when you're a sore loser in the sight of God

so..

don't do bad deeds.

completely avoid major sins.

disassociate yourself from evil-doers when you're not giving islamic advices to them.

reflect on oneself after a long day of daily matters and dealing with people so you know minor faults you might have done throughout the day.

yes, men forget. so be reminded...

..in prayer

..in supplication (du'a)

..in silence.