Some tips:

1. Go to the restaurant manager several times, then find the purchasing, and then find the restaurant manager. Go back and forth at least three times. It's hard not to succeed.

2. Take something with you when you go, such as cigarettes, fruits, specialties, samples, drinks, etc.

3. Don't talk is to sell your things, talk more, talk less about products, and don't always remember your beef. Everyone knows what you mean. If you do it, things will naturally be sold.

I hope I can give you some ideas. Good luck!