Before you meet with your employer, prepare what you want to say.
Write down what you’re unhappy about and what you want to achieve. If there was a specific incident, make note of the date and place it happened and how it made you feel. Describe any conversations you’ve had about it with anyone since then (don’t mention conversations with your lawyer or doctor).
List the three main points you want to make. This can help you figure out what’s most important to you, and help you remember what you want to say.
Before you speak to your employer, think hard about the outcome you want. How do you hope your employer responds? One way to think about this is to put yourself in their shoes. Ask yourself: What would I do if I were them? If you can make reasonable, concrete suggestions, you’ll give your employer something to work with. You’re more likely to get at least part of the solution you’re after.
Gather together anything that supports your position — any emails or letters that relate to the issue, your paystubs (if part of your pay was missing, for example), your written employment contract (if you have one). If there are any specific laws that apply to your situation, make sure you understand them and consider if you want to raise them with your employer.
In private, rehearse what you want to say to your employer.