Keep your opening card on the table, exposed, until you have had a chance to think. However, that is not foolproof, so the better way is to make sure that your partner (and you, when the positions are reversed) takes his time before playing to trick 1: this should be a universal rule, and it is not a strain: I am not suggesting a huge tank, just a deliberate and consistent tempo.
BTW, for what it is worth, against the majority of declarers, the immediate play of a
♠ suggests a stiff, and I would rise with the Ace and continue the
♦A and, depending on signal, the
♣10.
On most, but by no means all, hands, a declarer holding xx in
♠ will attempt to find out more concerning the opps' hands before committing himself to a
♠ guess. I would go so far as to say that against 90% or more of good declarers the immediate
♠ is a singleton if only because most declarers would at least take a few seconds to judge whether a trick 2
♠ play was better than trying to find out where the cards lie.
Of course, a really fast thinker/player (like a Sontag) will always have an edge here
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
Help
P-P-P-1♥
P-1♠-P-3♥
P-4♥-P-P
P.