When you start wearing them, take notes - anything good or bad, note the situation, what you heard, what you were supposed to hear, what environmental sounds messed it up, what was the environment, with whom you were speaking (known or unknown person), from which directions came which sounds, the more details, the better. Try to notice if there are specific vocals in speech you didn’t catch, or other sounds that sound weird.
Reason to notice good stuff is to be aware if after adjustments for the correcting of the bad you’ll report, previously good go worse, then you’ll know exactly what changed and not rely on memory or feeling. Because, chances are they’re false 
Fitting is a collaborative work of you and your fitter. His task is to decipher your complaints, your job is to be as precise as possible and test in many situations, but also, don’t forget to train your brain intentionally - like with audiobooks and such, where you’re focused on listening and comprehension. And not just focus on testing aids in everyday situations. That also is a training, but direct streaming is a game changer if you didn’t have it before, and every month you intentionally train, you’ll notice general improvements how your brain is getting better with them. Wear them 8+ hours a day, stream from your phone, tv (ideally, using tv connector), and push that brain to squeeze the most out of them. They’re great aids 
And obligatory c/p:
If you haven’t already, I suggest getting some basics through these two sources
best practices summarised by dr cliff5
https://blog.valuehearing.com.au/news/must-hearing-aid-features
https://blog.valuehearing.com.au/news/do-i-really-need-expensive-hearing-aid
And they have article about listening in noise, also recommended to read.
Both sources have youtube channel if you like that media instead.