Hi,
Regarding shipping company you have a few options. PostNord, DHL, Schenker. I think most people would go for PostNord.
Package should be big enough to fit the item in question, and should be well packaged, all around, to prevent it from moving around.
For parcel dimensions, check here:
https://portal.postnord.com/skickadirekt/?toCountry=SE&produc...
If you want to ensure the buyer, take pictures of the item in the shipping box well packaged, and then after it's been sealed. Get paid before you ship anything. Make sure the package is ensured, incase they lose it(PostNord). It says it's covered up to 50K, but not really sure how their policy works regarding that.
Taking pictures of the item in its current condition would also not be a bad idea. Incase someone says "This dent wasn't visible on the pictures" You get the picture.
Not aware of PostNord or any other place offering any type of "package content validation".
Assuming you're selling the 3060 Ti. Buyer looks legit. Any If you want to feel extra "safe" exchange information with the party where you can both validate the other person in some shape or form, If not already done.
Personally don't have to much experience shipping stuff to people as I only do pickups myself.
