On not being attached to the outcome

I really like some of the ideas in the Susan Jeffers "embracing uncertainty" book, but they are more of a stretch for me than I've found her other books. It will be a while til I've got the hang of some of it as I'm trying to turn around a lifetime of worry!
The latest chapter I read considers attachments. Now as someone who has practiced attachment parenting and believes life is all about relationships, I feel a bit challenged. I think she's all about relationships too tho. She writes about being loving and open and despite the trickiness, I do see what she's getting at. She notices how when we are focussed on a particular outcome, it gets in the way of going with the what actually is.
In thinking about hosting a party for example, she suggests that if we are attached to the outcome we get nervous, don't enjoy it until the release of tension after it's finished, and radiate that tension. Whereas if we are in the present moment and not concerned with how it works out then we are happy and excited, enjoy it and radiate love. If the party goes well we are glad and if it doesn't we know we can't control other people's experiences and just keep sending out loving energy and are more open to the possibilities.
I know people who have been happy in adverse situations, and know that even when my life has been tough I've still experienced joy and love and felt grateful for so much. So if we put in effort, whilst enjoying whatever process we are part of, work family or whatever, then let go of the success or not of the outcome, we're free to stop worrying, knowing that it's possible to find happiness whatever comes next.
Whilst I'm beginning to contemplate this for myself, I've not yet worked out a way of interacting with others that's not based on this. All my texts, emails etc revolve around wishing people well, which whilst lovely, could be seen to be invested in positive outcomes. "hope it goes well" for example is pretty much how I write. I'm not sure about radically rethinking this. I'm going to start with me and then figure how to translate it into my conversations...