How to avoid being scammed online

[Girltalker2]

Sa dami ng scans, just wondering if there are tips on how to avoid being scammed online?

I don't usually buy online but sinetimes I want to. Kaso I worry Baka after payment, wala ka nang habol. Then may caveat pa sila no refund if di makarating shipment?!!?

So what are the items I have to check to know the seller is legit and reliable?

Bank account name?
Website?
Followers?
What is a track number?
Instagram account - what if I don't have this, pano ko itrack order ko?
I'm hoping seller has Viber or what's up. Pero text lang puede sa phone nya?