The best way is by connecting to your own node, no doubt. The second best, is by using
Tails. It comes with Electrum pre-installed and does not allow you to sync without going through the Tor network. However, note that by doing that, all of your addresses can be linked from the Electrum server that you use to request information.
You must not connect to a third party server when using electrum, and you must not use a full node wallet for better privacy, you can use your Electrum wallet and connect to your own Electrum server, without exposing your ip addresses and BTC addresses to any third party server.
The only way to not expose IP and Bitcoin addresses to a third party is by running a full node, so I presume you've mistyped.