I think people don't take too seriously the opportunity to play correspondence chess. With three days per move i'm expecting to play blunder-free games (not in absolute but at least the most obvious ones!). Nonetheless, of the six or seven games I'm playing I'm winning half of them (possibly more) because of simple tactical blunders. I'm talking about mistakes that i'm not expecting to see in a correspondence game (unless the "blunder" is actually the only move), for example:
- self pinning the king so that another piece can be captured for free
- moving a pawn so that a square/piece is no longer defended and material gain is possible
- leaving pieces en prise (this really is a blunder i'm not expecting to see in a correspondence game)
So my advice is:
- You can move the pieces! Try out a few variations before submitting your move!
- Find games in the opening you are playing. Even only one, just to see how the opening should be played and get an idea of the possible middlegame.
- write notes for your move! BEFORE you submit the move. You have all the time! It is important because: a) after the game you know why you made a move and that will help your analysis; b) during the game, writing down the reason why you are making the move, you may realize that the move you want to make doesn't make sense!
- don't waste your opportunity to get better with an obvious blunder. Double check your move before submitting.
I'll post an example from one of my own games. I hope not to offend the other player.
I hope you can see my point.