The Manner of Counting Tasbih on the Fingers After Prayer
Regarding the manner of counting tasbih on the fingers after prayer: it has been reported in the hadith of 'Abdullah ibn 'Amr ibn al-'As, "I saw the Prophet ﷺ counting the tasbih with his hand." Another narration says "with his right hand," but the wording "right hand" is anomalous (shadhdh); what is authentically preserved is "I saw the Prophet ﷺ counting the tasbih with his hand." It has come in Abu Dawud, "We counted tasbih with the fingertips," but this is weak.
The hadith of 'Abdullah ibn 'Amr can be understood in one of two ways: it could mean he counted tasbih with his hand, meaning counting is legislated with the hand, so that it is not legislated to count with anything else. This would be clarifying the general type — as if he ﷺ were saying he did not count with pebbles, nor date-stones, nor anything else, but counted with his hand. Or it could mean specifically the right hand, based on the general hadith of 'Aisha, "He loved to begin with the right in purification, in combing his hair, and in all his affairs."
Most scholars lean toward this latter view — that counting tasbih is recommended with the right hand — though no specific wording has been transmitted from the Prophet ﷺ on whether he counted with the fingertips or by closing the fingers. Since nothing has been established from him ﷺ on this, the matter is broad, and what matters is achieving the count, whether with the right hand or with both hands, and whether with the fingertips or with the fingers closed.
The Sunnah is to count tasbih with the hand, since 'Abdullah ibn 'Amr ibn al-'As mentioned nothing else — meaning counting is done with the hand and not otherwise.