Some suggestions:

-- the book "Willpower" by Baumeister and Tierney

-- this article: http://happiness-project.com/happine...-something-up/ It says that some
people do better if they quit something cold turkey, while other people do better
if they cut down to a small amount of the habit. Find what works for you.

-- Start one new habit at a time. the "Willpower" book says willpower is like
a muscle: it gets tired, but gets strong in the longer term with exercise.
Trying to start too many new habits at once is more likely to lead to the
willpower getting tired and giving in (but don't use that as an excuse!)

-- Make a list of reasons not to do the thing, and put it where you'll run into
it when you go to do the habit. For example, taped around the outside of
a package of cigarrettes; or get in the habit of pulling the list out of your
pocket and reading it just before entering the corner store to buy cigarrettes.
If you don't think about the habit, you don't have to look at or think about
the list either.

-- For chemical addictions, I've read that it helps to have plenty of vitamins
especially vitamin C.

-- I read somewhere that for both chemical and behavioural addictions, they may be related to
"reward deficiency syndrome" and may be helped by DMAE which you can
get by eating sardines.

-- If you want to quit drinking and smoking, some people find it works better
to quit drinking first. Otherwise you might forget and smoke when you're drunk.

-- Come up with activities to do instead, or to do immediately upon stopping
each time. They can be quick little things like laughing, singing a song,
swinging your arms and taking a couple of deep breaths, etc.

-- Tell people what new rules you've set for yourself; this puts a bit of
pressure on you to follow them

-- Hang around with people who don't do those habits, at least for the
first few weeks

-- Set rewards for yourself