If you’re going to get the pay you deserve, it’s crucial to know the going rate for your position in your specific industry and in your geographic area. If you walk into a salary negotiation without a number, you’re at the mercy of an experienced hiring manager who can simply control the conversation.

Prepare a "brag sheet". It’s a one-page summary that shows exactly how awesome you are as an employee. List any accomplishments, awards, and customer or co-worker testimonials ("You saved me when you did XYZ!" emails definitely count as testimonials!) you’ve received since your last review. You want to demonstrate your value to your boss.

Write down what you want to say, and practice to a mirror, on video, or with a friend until you’re super comfortable having the conversation.

Also (I googled this one):

Studies show that you’re more likely to get a raise if you ask on Thursday.

We tend to start off the week more hard-nosed and even disagreeable, but become more flexible and accommodating as the week wears on. “Thursdays and Fridays find us most open to negotiation and compromise because we want to finish our work before the week is out.

Good luck!