See below for useful links to www.rhosjudokwai.co.uk website with photos of how to fold a judogi and how to tie up your belt:

A tatty or dirty judogi is considered a sign of disrespect in many dojos, therefore care should be taken to prevent creasing etc.
In order to do this the Kodokan teaches judoka to fold their judogi in the following way:
LINK to website (opens in new window).

Another sign of disrespect is a badly tied belt. Now courtesy of Rhos Judoka Gareth Love, theres no excuse:
LINK to website  (opens in new window).