Figure out on what to focus.
Schedule when to focus.
Following though with this focus.
Continue on iteratively more specific levels until you know the very specific and immediate task and focus on it.
Focusing in this way is a nearly universally valuable skill that I have never known to be taught.
Example:
I want to be good at basketball so I must focus on practicing (not playing).
I decide to practice from 5 to 6 PM at the YMCA.
I go to the YMCA
I then decide that I want to improve my ability to attack the rim.
How, using a spin move.
How do I practice a spin move?
The components are:
1. Getting the other player leaning
2. Moving the ball to the hand opposite the side I'm spinning toward
3. Taking a large step with the foot on the side I'm spinning towards past the foot of the player I'm spinning past.
4. Pivot quickly on the planted foot with which the large step was taken while controlling the ball with the opposite hand in a single dribble that is continued with the hand on the side being spun toward.
5. Take another large step and likely one more dribble with the same hand being spun toward.
6. Pick up dribble, likely with the one hand and finish with a layup or pick up with both hands and pull up for a jump shot.
Now try to do the whole spin move quickly. After imperfection figure out what component was imperfect first and practice it both in isolation and as part of the entire move. Each component can be broken down into a similar list of components.
For example, how to I get the other player leaning?
1. Inside out dribble
2. Fake crossover
3. Forward between the legs dribble
4. Backward between the legs dribble
5. Behind the back dribble
Each of these fakes has intricacies. The skills and sub-skills on which to focus are endless. The relieving result of focusing on the components is that when practiced they will meld together in unexpected yet brilliantly productive combinations when in the flow during the heat of battle.