Dan Heismans recommended tactic training applied
... not only for beginners! See http://www.chess.com/forum/view/general/dan-heisman-says-this-about-tactics-training
One can apply this to higher levels as well (faster, higher percentage, higer problem ratings and viewing the board from the opponents site ).
So i started with that 900 - 1250 set and with the view from the opponent, because i want to spot his possible tactics in fast time as well.
With chesstempo i did the following steps:
1. go to the preferences and set the board to "player at top"
2. create a problem set
3. have fun with it