Sorry if that sounds a bit alarming! What I mean is, after the summer break, you might find that your usual tactical sharpness has gone a bit rusty.
To get back to your normal diamond-honed sharpness, you just need you get your eye back in with some practice.
Some things to practice are:
I remember a story from Dan Heisman:
“One of the most important ideas involving safety is that basic tactic skills should be used to prevent an opponent’s tactics, not to find winning tactics for oneself!” [or at least - not just that - DR]
"Unfortunately, I have found that this idea is either misunderstood or continues to fly under the radar.
[...]
...a typical 'Class B' student that I had a few years ago. I suggested he start by studying the basic tactics in John Bain’s Chess Tactics for Students, which he subsequently purchased. At the next lesson, he began by politely shoving his copy of the book across the table at me, saying “You’ve got to be kidding. These problems are way too easy for me!”
I proceeded to examine two recent games he had lost, and it turned out that both losses were primarily due to overlooking, and thus allowing, his opponent to play a basic tactic. After the second game, I said “I don’t understand. You said that Chess Tactics for Students was too easy for you, but are you saying that the two tactics that caused your losses in these games were more difficult than the tactics in this book?”
The student stared at me for a few seconds. Then he reached across the table, grabbed the book back, and quietly admitted “I see what you mean.” To be fair, this student’s attitude is typical of most players near his level.
After hearing this story, one could argue that it was not my student’s lack of familiarity with the patterns, but his lack of a Real Chess* thought process that was his main problem. And that could be true – thought process and pattern recognition go hand in hand. But it is also undeniable that the more familiar you are with a pattern, the more you will avoid allowing it for your opponent, no matter how poor your thought process."
* That is - "If I play this move, can I meet all the threats that my opponent can make with their reply?" - DR