Keep your swimming fun
Fun and speed go together
Have clear goals
You can't get to where you want to go unless you know exactly
where that is. The more detailed a picture you can paint of this
goal, the better your chance of turning it to reality
Make your practices important
You will compete the way you practice. Practice does not make
perfect - Perfect practice makes perfect
Focus on your race one stroke at a time
Stay in the present. Concentrate on what you are doing, while you are doing it
Concentrate
Concentration is the key mental skill to swimming excellence and mental toughness

Learn to loose
Learn to quickly let go of your mistakes and failures. Don't dwell on the past. Learn the lesson and go through it

Use your imagination
Focus on exactly what you want to happen, not what you're afraid will happen. Make your
pictures as vivid and detailes as possible - seeing, hearing and feeling yourself performing just the way you'd like it
Let it happen
If you make your race too important, you'll get into trying too hard and will swim slower. Trust what you've done in practice
Program it well
You swim the way you think. Learn to "program in" good stuff and that's what you'll get back out.
Be positive
Practice being positive about yourself, teammates, coaches... no matter what. "Can't", "never" and "impossible" do not exist in the dictionary anymore.
Reframe adversity
Learn to look at obstacles and setbacks as a way to get more motivated and to increase your confidence. When your swimming gives you lemons, make lemonade out of them!
Learn to relax
In order to stay within yourself and swim your own race you need to have the ability to handle pressure. Probably on of the best is to learn to slow and deepen your breathing.