Plus, the time of the month can make a difference. I also take some pain relief 45 minutes before and TUMS 20 minutes before. Less caffeine is better, too.  

You may want to consider sugaring, if you live in an area that offers it.

Before
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1) Exfoliate in the shower the night before. By removing excessive skin, the wax can stick to the hair better.  
2) Take an Ibroprofen about 20-30 minutes before your appointment. It helps relieve the pain during and after.  
3) There is topical numbing cream that you can buy in stores and online. Some salons don't like you using it though. I normally use Sally Hanson Ouch relief Numbing wipes. They aren't the best, but the tech doesn't seem to notice and I haven't had issues with irritation or anything afterwards.  

During
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4) Breathe. Don't hold your breathe when she pulls.  
5) Put your earbuds in and jam to your favorite songs. I'm not sure if it's because you can't hear that ripping sound or what, but it's always made it so much easier for me.  

After
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6) No hot showers or baths. Keep the water as cold as you can stand (which makes your hair look much shinier too!). Also stay away from pools and hot tubs.
7) Apply Neosporin or Aloe Vera gel that night and the following mornings/nights until the irritation is gone. With that being said, try to wear loose clothes for the next couple of days without undies so it doesn't get rubbed off and doesn't irritate the skin further. Since I work M-F, I normally get waxed Friday evening so I can wear loose workout shorts over the weekend.  

Between Waxes
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8) Keep your skin moisturized. This will keep your skin soft, but also the new hairs growing, so your next wax will not be as painful.
9) Let your hair grown to about 1/4 inch before getting a Brazilian or bikini wax, but no more than 1/2 inch. Since many providers go completely nude down there, you can wear cute boy shorts or undies through most of your date while your hair is growing in. Most guys don't seem to mind, but you may want to give them a hint if you get the impression that it would bother them.  

 
Hope this helped some :-

from a hobbyists perspective, its well worth it to me for whatever torture you have to go though to get waxed.  Waxing inspires me to create a DATY masterpiece.  Do I sound shallow?

spent months getting a quarter of his body tattooed with very deep and intense colors. When done, it was magnificent. He lived in LA and would fly up to SF to have the work done over the course of more than 6 months. He could not finish what was planned for the rest session and asked me for help. At the time he was young and healthy and with no positive medical history.  
I gave him some heavy tranquilizer and some heavy pain killers,  He would arrive at his sessions stoned and with good pain blocking.  It allowed him to have a work of art created on his body

Find A Really Great Wax Girl & I like hard wax

I have a preference to hard wax because it only sticks to your hair and not the skin. Your hair needs to be not to short and not too long. Yikes if they have to do multiple rips to the same area. I'm generally pretty calm but when that hot wax is going around the labia lips I just really hope no wax runs. I've been looking into laser but can't find any solid results for the price.

I get waxed every four months.

IDK, perhaps it's my high pain tolerance but my experiences haven't been as painful.  I think it has more to do with the esthetician I go to.    

I usually take some Ibuprofen before going in.  Make sure I haven't had any caffeine several hours before my appointment as that makes the skin sensitive