Using idioms (somewhat colorful/colloquial):
'The event was planned down to the last detail and ran (as) smooth as silk.'
Changing the subject (going active):
'After months of meticulous planning, seeing to every last detail, the committee breezed through the event, a complete success enjoyed by patrons and planners alike.'
Matter of fact:
'The event was well planned, down to the last detail, and ran smoothly throughout.'
'The event ran smoothly as planned, down to the last detail.'
There are many wording options; that is subjective, and I offered a few to show different takes on it, not great wording options. But regarding word/phrase usage, I did find "felt like a breeze" used in similar contexts online, often in this structure (paraphrased for example): 'After all that planning, the wedding felt like a breeze.' Or with naming specific tasks: 'After preparing all those invitations, hosting the party felt like a breeze.'
- Merriam-Webster (down to the last detail)
- Collins English Dictionary (well planned)