Preparation is toward fulfillment of the objective. Preparation is not toward perfection.
Measure the success of your preparation less in terms of polish and more in terms of proficiency. Did the thing you made do the job you made it to do? Then that’s enough.
Could it do the job better? Optimize and enhance by all means, then. But keep the objective in sight. Don’t be distracted by sheen. If the sheen is what people notice about your work, it’s probably not having the kind of impact you want it to.
All this to say I have a volunteer training event this weekend that needs to accomplish some important objectives. Impressing the participants with slick presentation, however, is not one of them.