Probably the most effective way to boost your Will Power would be with a session of Hypnosis.  Well I would say that wouldn't I

It just happens to be true.

There are also other things you could do that are not quite as effective as a professional tailored session but here goes:-

You can learn self hypnosis that's a less costly approach and can be used for several things as well as boosting your will power.

You can get into routines and make lists which helps keep you focused.  The secret is to give yourself a little bit less than you can manage so you never become overwhelmed.

One way you can help to get into the habit of dealing with things more robustly is to practise every day on little things that are easy to manage but that you consciouly decide to do.  This way you become programmed in dealing with things straight away and then when big things come along they are easier.

These suggestions can all help a little but not really with things you want to stop like smoking or over-eating.  Have you ever noticed that if you get a thought in your mind about a tasty treat or even chips and you try to use your will power to resist, even though you do the thought remains and keeps popping up - even for a few days or a week or so that eventually you no longer resist.

For things like that it is definitely the imagination that is what you need to address.  This is where the skill of the therapist comes in as they can design  a suitable and alternative thought.  But you can also have a go yourself.  Think about why you want to resist in other words what are you gaining and thing about something similar that will enhance the result of your resistance.  Now imagine that in your mind and keep imagining  until its the enhancer that you start desiring.

Your imagination can by pass a lot of the suggestions above too.  If you can imagine your goal and it is tested to be suitable and attainable then if you imaginereally well and often you won't need your will power as your enthusiasm from the imagination will push you forward.

If you decide to try some of these methods please do let me know how you get on.  I am interested truly.