Affirm: speaking slowly helps to make the other party speak slower. Likewise, assuming a foreign and/or bizarre accent may get them to pronounce more clearly. Works especially well in multi-language areas.
Negative: above all, you should NOT be ready to hear what you think you could expect to hear.
Tip (repeated): get a cheapish receiver and go listen what happens at nearby aerodromes. Yes, plural: there may be much difference between local traditions. Try mentally answering before hearing the intended replier - but do NOT hit that talk button (I had to tape off mine).
Tip: next-room practice with an instructor sounds like a good idea, if you can turn up an instructor willing. Failing that, you could even practice with another student, perhaps taking each role in turn - if you do take care to record your sessions, for later discussion amongst yourselves AND with a party of authority.