Also a regular Vinted buyer / seller and have learned a lot over the years.
New with Tags - can be an item clearly worn but with the original label fixed to the tab with a safety pin.
New without Tags - are often worn
Very Good - meaningless often has marks / stains
Stock Pictures for an item - meaningless - I want to see the actual item I am buying
Screwed up wrinkled clothing - at the very least demonstrates how they have been stored and I wont pay an almost new price for such items.
Duplicate pictures on several different accounts, often with back to front labels and no seller reviews = almost certainly a scam. These seem particularly prevalent on Toast listings probably because Toast items are expensive.
Non arriving items - the reason I always ask for Royal Mail when buying and ship my items Royal Mail. At least I can track.
Seller sending the wrong item, always inferior to what I have paid for and always ‘woops, I made a mistake’. Total rubbish and I always report and ask for a refund.
Having said all that I have bought some great items at reasonable prices and sold a lot of bits and pieces. The key to Vinted is to carefully look at the pictures, check the seller reviews and work out how many are written rather than automatic reviews, check out the whole seller listing and other items for sale, ask questions, request extra photos if necessary and track delivery.
If selling, be scrupulously honest on your listing about the condition, photograph any flaws, stains etc, photograph the item in the box / bag on a set of scales to prove the weight and ship via a method that records the weight and delivery.
Also understand that if you sell NWT items at too low a price they may be immediately relisted with the buyer profiting from your lack of understanding of the items true worth.