As we have over 5 million recorded games of chess known to man, they present a huge reservoir of ideas and precedents of what has been played, correct or wrong. It would be useful to look at past games to derive ideas and innovate on what's played to try something new yet based on solid fundamental ideas played by the past players.
Somehow in the games I've played with the juniors, I can discern that they have played lots of games and hence their practical ability to spot tactical threats is strong. However, when it comes to making strategic decisions to steer the game in their favour, they seem to hit a blank. I attribute this to spending too much time studying variations but not full games. One of the main areas of study in my opinion for a competitive player is not just to learn the variations but also the games of how the variations may turn out. Playing over master games based on the variations will allow the player to have a preview of what's to come, what positions to envisage and particularly the endgame possibilities that may occur. So memorising full, useful key games in the variations played can be useful in allowing the player to develop new ideas based on older ones.
A case in point - my game against WIM Gong was indeed based on a famous 19 mover sacrificial attempt by Edward Lasker against Sir George Thomas which is usually found in every book on attacking chess. It was a masterpiece of how the King was dragged from its castled position all the way into White's first rank and mated there. With that in my mind, I am sure that even if the moves were not all duplicated, the attack that arose should be sound enough to venture a try. The same thing goes when we hazard a sacrificial try in our blitz games - it has to be based on some presidential game in the back of our minds, with the rough details of the continuations. Interestingly, I just saw a puzzle in another blog and readers asked to find the move by Black that wins. This was played by Dr John Nunn against a Singapore IM. Without giving too much away, all it takes is for the interested reader to look at the famous game Averbakh - Kotov, Zurich 1953 and they will figure the moves out. I am sure Dr Nunn must have had the Kotov game in mind before he ventured his idea.
So rather than spend time taking part in tournament after tournament, my advice to budding players is to read as many games played by the masters in their openings to develop their knowledge and feel for the positions they are about to play. This will give them ideas to work on in their games and confidence to play the moves they want.