Deep Throat Tips???

I've tried, and tried, and tried...and I just can't get his cock down my throat without gagging as soon as it touches my throat. Please share any tips or anything that helped you. I just want to be able to swallow his cock once in a while...what helped you when you finally succeeded in doing It? Tips, tricks, whatever you got, I want it!!! His dick is fairly big too, 8 or so inches I'd say.