@pluto, glad you made it in; Welcome, to the path of security, and liberation.
To store your Safe Exchange Coins offline, you could need to put them into a regular Bitcoin Address. You Must control the private key. To keep things simple we have on the Safe Exchange main website a bitcoin key maker that produces you a key pair directly on your computer therefore, they are secure. Here we go:
1. Go to https://safex.io/keys
This will generate for you a pair of random keys. Copy down the private key and the public key for future reference. Once you leave this page those keys can never be recreated so please do copy them down perfectly. This is after all crypto currency and this is how it works.
2. Copy the “public key” into Bittrex: that you made on the Key Maker on the safex.io site into your withdrawal screen in Bittrex. Be sure that they correspond correctly to the address that you created previously. Then hit the “withdrawal” button.
3. Finally you can check your balance/status of the withdrawal on Omnichest.info - Property Lookup Safe Exchange Coin is property #56 on the OmniLayer. You can also simply copy your address into the search box to see if your transfer has been completed.
If you have any other questions, we’ll be glad to help you. Welcome again to the team 
Edit: if you buy using safex.io , you will be deposited to an address that you supply or generate one in the process. This method also is supported by SafeExchangeCoin (SAFEX), USDT, MaidSafeCoin, Synereo Amps, SEEDs, and any other omni coins.