When it comes to radio calls, there's always room for improvement...

1) Know when to expect a radio call.

This will come with experience, but knowing when you should be expecting a radio call will minimize the times you are caught off guard. Reducing open loop communication also reduces the number of radio transmissions that need to be made.

2) Speak clearly.

Aircraft radios are already scratchy and hard to hear. Having vocal clarity reduces the chance of someone not understanding your transmission. Speak clearly, and don't talk too fast.

3) Write down key information.

ATC often transmits long clearances that include taxi directions, IFR clearances, etc. Be prepared for when they call you, and write down the important information.

4) Use proper terminology.

Not only is it implemented to help reduce miscommunication between transmissions, but it also reduces the time it takes to transmit your intentions. Not sure how you should say something? Check out the Pilot/Controller glossary.

5) Keep the microphone close to your mouth.

As the microphone gets further from your mouth, it can start picking up more background noise, and less of your voice.

6) Think of what you want to say before you say it.

Doing this helps you transmit a clear message and avoid making transmissions longer than they need to be.

Here's a template that helps: "who are you talking to, who are you, where are you, and what do you want?"