How often you continue with you question even when it should have got over with the first sentence?
For example,
‘Can you please point me towards the data sources for these attributes? Umm…will ‘Zappex’ be the best portal to look at for the data or you think something else would be better?
Shall I ask permission from Ravi for doing that work? Or, may be, at a later stage?
Try to get comfortable with that pause after your question, the silence that follows. Allow your respondent to think; don’t jump in with possible answers after a few seconds pass. Once a well thought out and a well articulated question has been asked, the onus falls on the listener to come up with the answer or a follow up question. Respect this fact for getting the right answers.