How can a Muslim avoid showing off and self-admiration in his good deeds and acts of worship?

If a Muslim is afflicted with self-admiration (ʿujb) or ostentation (riyāʾ) after a good deed, he must cast it away and combat it by seeking refuge in Allah from polytheism (shirk) and asking for forgiveness. He must bring to mind sincerity (ikhlāṣ), seek forgiveness (istighfār), and remember that strength comes only from Allah, and that Allah alone is the One who helped him complete the deed. One should not abandon good deeds out of fear of ostentation, because that is from the steps of Satan to discourage the believer. As for rejoicing in a good deed, it does not contradict sincerity and faith; rather, it is a sign of happiness and success. And if people praise his good deed, then this is an immediate good tiding for the believer and an indication of Allah's love for him.