Marianne Williamson's Miracle Thoughts emails and podcasts are interesting and useful, via  Although she makes all sorts of spiritual allusions to the universe and a higher power, I screen that out and substitute my higher brain and other things that I think have truth.

I liked her Let Go Of Attachments podcast.  Some of the ideas were:

If I'm not attached to the outcome (don't feel that I must have it to be happy) then I won't be motivated to create it.  But not being attached will not make you into a lazy bum.  The desire to progress, from the higher brain, is sufficient to have you go for what will benefit you.

And some things will happen and some won't.  The higher brain will tend to self-organize and give some  good input if we direct our attention and write out (or listen to) what the higher brain reasons out or suggests. 

Undesired outcomes need not determine our happiness if we recognize that a big part of life, one of the givens, is that we will have undesired outcomes and that that is a "so what?!"  "Overall life is good on the average and I can live without many of the extras in life, as I can intentionally choose to be happy regardless of what occurs.  "The reason I choose to be happy right now regardless of any outcome is that 'Life is good! And I get to experienc it!  And there is plenty in my life!  And I am so grateful!'"

One of the disadvantages of attachment, she points out, is that we may try to control things inappropriately (and/or make ourselves tense in the process of feeling we have to control it to avoid the consequence of being unhappy because we told ourselves we would be unhappy if we didn't get it. 

We become attached to things because we think they will get us what we want, which is ultimately happiness (or some form of not-unhappiness), but if we use the means we have to create happiness intentionally, we will already have the end result we want and the good outcome is only a bonus but not a necessity.