Fatawa of Ayatullah al Uzama Syed Ali al-Husaini Seestani
958. The recommended precaution is that one should not join Takbiratul Ehram of the prayers with any preceding recitations, like, Iqamah or with a Dua which he may be reciting before the Takbir.
960. It is necessary that when a person pronounces Takbiratul Ehram, his body is steady, if he pronounces Takbiratul Ehram intentionally when his body is in motion, his Takbir is void.
964. It is Mustahab for a person pronouncing the first Takbir of the prayers, and also the Takbirs which occur during the prayers, to raise his hands parallel to his ears.
966. If after having pronounced Takbiratul Ehram, a person doubts whether he has pronounced it correctly, he should ignore his doubt at any stage.