Electrum 2.0 supports a new make_seed command line option that generates a random seed and displays the mnemonic:
Electrum is a deterministic wallet where all bitcoin private keys are derived from a single seed. That means that you only have to backup the seed once and it’s good for life. It also means that should the seed be compromised all your bitcoins can be stolen. So let’s look at how electrum seeds are created and secured.
Updated: 23 October 2016
Coin control means to have granular control over the inputs and outputs of a transaction using the Graphical User Interface (GUI) of a bitcoin client. Not all bitcoin clients support coin control. Electrum is a client that has limited support for coin control.