With regards to tapering and finally quitting, here is the psychology
I used on myself, that worked.

When you try to quit cold turkey, the last pack can be hard to reach.
Every time you get to the end of a pack, you get agitated and want to
buy another one, thinking to yourself that you will quit after THAT
one runs out. This is a perpetual motion machine, and you will
eventually give up trying to quit.

It's very important to break this dynamic of needing to replenish your
supply as soon as (or before) you run out. Let it run out. Plan on
doing without for a while after you run out. Wait as long as
possible. Try waiting a whole day. Make it a policy not to buy a new
pack for a day after you run out. This will really build your
willpower, without too much sacrifice. As I mentioned in my other
post, increase the number of days you do without.

It's not important to be 100% successful in these day to day wars.
Instead, look at the big picture and where you're heading. You know
you want to quit. So the first step is understanding that you won't
drop dead if you don't have a cigarette for 4 hours. So, actually try
it. Steer in the direction of quitting. Eventually your own nagging
pressure will win out, if you give yourself attainable goals.

Sorry if this is redundant, but I feel better for having said it.

-Ed