Thinking about what?
"Concentrate!" "You have to get your head in the game!" and other unhelpful phrases. These vague instructions rarely work unless the athlete has a strategy and the skills to do that. 'Concentrate' is a suitcase term - lots of different meanings for different athletes. So you're on the right track but not specific enough. And as for "Get your head in the ...." What does that even mean?
So I have a few ways to deal with this subject and they come under the general heading of 'Thinking skills'. Like any skill, they have to be taught and they have to be practiced. And not just practiced now and then or in games, but a lot and in games. How many free throws do you need to get a good technique. Some coaches would say thousands. And we do know the mechanics of a good free throw. But how many times is the shooter practicing helpful thoughts to bring the percentage free throw stats' up to the high 80s and beyond.
First summary tips for closed skills (golf shot, free throw, snatch lift, tennis serve etc). Just before your step up: see yourself succeed, 'feel yourself' succeed, decide on a technical cue word (one only) and step up. Sounds simple: the idea is, the teaching is a little trickier. More in an upcoming post.
(photo source: CBC Radio)