Yes, there are things you should follow.
Do your research. Know who you are buying from.
If you get scammed, it is on you.
Overnight shipping does not mean you will get your package the day after you order. It means when it is shipped you should receive it the following day.
Communication is key. Confirm with the buyer on payment being received, set expectation on ship date.
If you do not get your order, COMMUNICATE with the buyer.
Do not come on the page and start bad mouthing sellers unless you have tried to communicate on 2-3 attempts and then receive no response.
I know the feeling of anticipation but be patient. For a lot of sellers this is a hobby, not a job.
Charge backs can be a slippery slop. If you received your order and request a refund, you will be banned.
We do not condone "brown boxing" request.
What you do outside of the forum is on you, and as stated before if you get scammed it is on you.
If you need a mediator, ask, we will do what we can.