Sharing an Asset
You can for example select objects to be directly sent :
Or select a specific Asset such as a Material :
Downloading an Asset
Then, just click download to get the asset. It will be saved in tmp folder.
Once downloaded, you can append it as many time as you want. Yes ! It is that simple !
Sharing a File
Sharing a file is pretty much the same, you just select your file in the File Browser :