Unlock the following hidden costumes which are found during various missions:

Unlock Classic Black Tuxedo:
In the Gpsy camp upstairs in the house where tear gas is on the lower level

Unlock Bond's Dinner Jacket:
Obtain it from Q's Head Quarters at the second part of the Hedgemaze mission

Unlock Russian Uniform (Russian solder's Uniform):
Istanbul Part 2 in the safehouse, the man there tells you it is in a chest.

Unlock Tailored Suit (Grey Suit):
Start with it in MI6 in Hedgemaze level

Unlock Covert Uniform (Stelth Suit):
Where last bomb is in Station

Unlock Bond's Snow Suit:
Obtain it in the Factory mission