Switch off the TV using the power on/off button on the TV itself. On many modern LED/LCD TVs these days which have a narrow bezel, the power button is often at the back (like my Sony), or under the bottom edge (check your TV manual but all TV's have an on/off button somewhere on the cabinet).
After switching it off with the button, you may then optionally switch of the supply socket or unplug it.
Because my Sony has the on/off button at the back (and it's a very small button) I never turn it off fully - - I just use the standby on/off button on the remote - much easier. I know being in standby mode it's still using electricity but that doesn't bother me - it's only a very small amount (5 watts according the book).
I only turn it off completely if we go away for a few days, but that's very rare now my kids have flown the nest.