Mindfulness and meditation are tools I use.
It is really empowering to learn to control what you choose to think about. Of course, some things have to be planned such as retirement etc. - but the gist of it is to observe the thoughts as they come and then if they are not useful in the moment, usher them out and replace them with positive thoughts of things over which I have some control, and which will increase and expand my life.
Thoughts are like waves, they come and they go and I just observe most of them. My meditation uses a visualization of calming the waters.