Whether you choose the warmer or cooler pool, starting is never easy. You can shorten the pain of entry by just jumping in and getting your head wet.
Have goals, yes, by all means have goals. But don't overwhelm yourself with big numbers. Rather, just think of the lap you are completing as you are completing it. As you complete that lap, repeat the next highest lap number to yourself until you complete that one.
When your head is under water, it is not the time to inhale, but rather the time to exhale all you've got. But, when your head is above water, don't let that opportunity to take a deep breath pass you by.
Sometimes while you're swimming, you forget whether you were in the middle of lap 12 or 13. Always believe the lower number of the two. By the end, you'll either have completely and honestly met your goal, or have exceeded it and not even known.
Be sure to include a swirly flip turn at each end of the pool. They break up the boring straight line and give you that extra boost to kick off the wall with more power than before.
If your lane partner is extra splashy, just close your eyes. Don't worry, they'll pass by shortly.
When water gets in your swim cap and goggles, drain them in the middle of the lane. If you do it at one end of the pool, you'll have to convince yourself to start up again.
If your heart starts to beat too fast, or you find yourself frantically gasping for air, don't stop. Just slow down. Become more deliberate in your stroke, and hold your head above water and second longer than you normally would. Your heart will calm down, and your breath will come back. And you won't have missed a beat.
When you've accomplished your initial goal, swim a victory lap! (Or two, or three...) Just because you can.
I love the lap analogy. I love swimming. And I love you.