Best Way to Transfer Files Between Laptops?

Yesterday I got my Eluktronics Prometheus XVII and I want to transfer like 500 GB worth of stuff from my old laptop so I can give it away. Any suggestions on the best way to go about this?

I have a 5TB external drive for my wife's files.

External HDD is by far the fastest and simplest way, and a 500gb-1TB should be reasonably priced if you don't already have one. If you don't have one and don't want to spend money, there's always network file sharing, but that takes a little bit of configuring to set up. There's also the various cloud services like Google Drive and whatever, but that can be pretty tedious.

Create a local wireless connection and send everything you need over the network

Can't you just plug an ethernet into them? That's how consoles have always done it and I assumed you could do it the same way with a computer.

We have a 16TB NAS as we are scared to have just one backup plus it's useful so everyone in family can access files/movies and such. Get a NAS IMO. Oh and destroy the hard drive/SSD in laptop you are giving away. Everything is recoverable unless you use really special programs which take days on a small HDD. But not with thermite, acetylene or a magnesium burn which turn it into useless molten slag in a few minutes. There are services you can hire which will do this for you.

I once destroyed a drive with a rather large magnet :)