*You should be in a gear that matches the speed your doing.
*You shouldn't use the engine to slow you down. Increase wear and tear on the engine.
*You should be in 1st when you come to a stop. Rather than trying to find first, under a panic situation.
*You should always have your brake applied whilst stationary.
Ah now the bad habits

*I do the cool down shift, no clutch, no hands jobby. Hehehe
*When I'm riding hard I down shift, whilst braking, using the engine to slow me down.
*Sit at the lights with no hands, not in gear, no brake, checking out the world.
Or you can do what Dan did leaving my work yesterday.
Pop a wheelie up the street, drop it down hitting the rev limiter, braking with a compression lock up at the end of the street.

NB: Just seen the bit about no clutch, down shifting. You can do it, but i wouldn't do it all the time. I use the clutch to down shift, but none for up shifting. (Sometimes i do to up shift, with pillion, or in traffic)