Answer:
Choose a thought. This can be anything. Hold on to this thought for 5 minutes. You should not let any other thought to creep in. You can make this a daily habit so you can switch to high concentration at will. Increase the length to about 10 minutes and focus on a single thought for this amount of time. Set small goals, Use sticky notes and make to-do lists, Meditate, Work-out, Memorize, Read, Keep learning.