Espionage

Do you spy on your opponents games in tournaments? There is a wealth of information to be learned!!

no, but thanks for the helpful hint. I never thought of studying their gameplay before taking them on in tournaments.

Here, no.  I've generally decided on the openings I'll use/experiment with before the start of the games.  Lately I've been running through a series of Sicilians Najdorf, Kan/Taminov, and now Dragon.  I might continue with this or switch to a series of Ruys-Steinitz, Open, Chigorin, Marshall.  Also thinking a gambit series.  In addition, lead time between announcement of opponents and start of the tournament is minimal.

In the ICCF, when there is time, I'll check out past history and get some idea if I need to brush up on odd lines or if I want to face either his e4 defense or his d4 defense.

yes, some of the time. very instructional, and I know what kind of game they dont like.

I am with CarlMI--here I just play my openings. However in the one tournament I played in I kept track of how everyone was doing and the style they played.

In serious correspondence games I spend quite bit of time on my preparation. Not only looking at my opponents opening choices but refining my own.

I wasn't really thinking of openings when I started this. I was really thinking of style. Here's an example from my own tournaments (I can't post the game because it is still on). I was Black and we had castled on opposite side. His attack was going faster because he was about to advance his pawns and trap my Bishop and if I moved it his pawns would go faster than mine. Fortunately I had seen in another game of his that he did not like accepting sacrifices so, instead of saving the trapped Bishop (sac 1), I took on of his King's pawns with my other Bishop (sac 2), and if he took the Bishop I could sacrifice the exchange (sac 3) on the open file to get a rook there quickly. If he had taken one of my Bishops his King may have escaped, but because he didn't my attack is going very quickly and both sacrificed Bishops have escaped.