With the recent hacking activity, and account locking, the only safe way to send Steem or Steem Dollars to bittrex, or any other user or exchange, like @blocktrades is through the command line interface, aka CLI_wallet .
In order to use that.. you will probalby need your windows miner which will be updated soon to 0.11.0, or a linux miner-seednode...
Go in the Cli and type
gethelp transfer
after that, the cli prints, the following result.
Transfer funds from one account to another. STEEM and SBD can be
transferred.
Parameters:
from: The account the funds are coming from (type: string)
to: The account the funds are going to (type: string)
amount: The funds being transferred. i.e. "100.000 STEEM" (type: asset)
memo: A memo for the transactionm, encrypted with the to account's
public memo key (type: string)
broadcast: true if you wish to broadcast the transaction (type: bool)
Than means in simple words...
transfer myaccount receiveraccount "100.000 STEEM" memokeyprovided true
transfer steemychicken1 bittrex "100.000 STEEM" memo true
Thats all!