I have wanted to do this for quite a while & I am so pleased that I dedicated the time to it.
I have learnt so much, thoroughly enjoyed it & have ended up with 2 new garments to wear.
Part of the reason this works is because you have nothing to lose
Gather your materials eg fabric, thread, pattern, tools, whatever you need
Make Space: literally clean up. Tidy up enough space to be able to do what you're going to want to do, clear the clutter, throw away the crap or at a minimum just stack it all somewhere else.
Make time : take time : take a half day, full day, 2 days, a week, whatever.
Dive in so deeply that you actually don't want to do anything else; that the day ending makes you sad; that you wish you didn't need to sleep; that you can't wait to leap out of bed in the morning to continue where you left off the night before.
Complete your project & marvel at the techniques you have learnt, the thing you have made, the experiment you have completed, your applied self.
Success is knowing that this is either the absolute end, the last time you will ever do this or merely the beginning; that even if you don't like what you made you have new skills; that if you don't continue immediately you will come back to it; that you can use the new techniques or skills to create derivatives.
Everything you have learnt before this has enabled you to get where you are now.
It's true, the more you learn, the more you are able to learn !
It's only ever dissatisfying if you went into your learning with a preconceived notion & what you end up with is different from what you imagined . . .
. . . bit like life really 😏