Easiest way to wirelessly transfer files between 2 windows 10 laptops?

Both Windows 10 on the same network?
If yes did you try to open C drive or D drive by IP and admin share?
\\192.168.1.100\c$  
\\192.168.1.100\d$
Replace IP with your Windows 10 IPs

Maybe you will have to switch off firewall for opening admin share.
https://support.microsoft.com/en-us/help/4028544/windows-10-turn-windows-defender-firewall-on-or-off

Hi there! :)

The easiest way is to enable network discovery and then on the folder you want to share, give access to specific people. You will need a network, preferably a protected business network you can share with to do that. If not, you can upload and share the folder on SharePoint and change the permissions to fit your needs from there.

if the PCs are NOT on the same network, some choices include:  

1. make a TeamViewer connection between the two, then you can copy files between them.  Note, TeamViewer is a remote desk top app, with manual file transfer built in.  To use for one time or occasional file copy.  If you need more constant access to files check 2 and 3 below.    Similarly you can use a product like:  https://winscp.net/eng/index.php to transfer files between systems manually.

2. Use a cloud drive, like dropbox or one drive here is a list:  https://www.techradar.com/news/the-best-cloud-storage

3.  Use cloud drive mapping.  Here is a good description, with links to a some of the products available.  See:  https://www.itprotoday.com/object-storage/cloud-storage-solutions-mapping-storage-network-drives

wirelessly transfer files  --  other than usb saving and moving the usb stick to the other computer.
Without a router enable internet connection sharing on one of the laptops wireless adapters .. connect the 2nd laptop to the SSID that you have setup when you enabled ICS
Windows 10 setup a hotspot
https://www.webnots.com/how-to-share-internet-connection-in-windows-10-computer/
Then follow the advice above about setting up shares

is this for a one time operation - or a connection that will be used frequently?
for a one time operation - you can use Teamviewer

sorry for the delay.  

both laptops will be windows and on the same network.  

can I have a simplified answer pls?

If both are on the same network, just copy between them directly.  You can either create a shared folder that each can use or just use the public folders already present.  

Make sure on each PC:  

1. The workgroup name is identical
2. The network connection is set to private or home
3. Network discovery is turned on

You shold be good to go.