This is something I learned in Sidney when I turned two large back yards into a Back to Eden garden. When you get free wood chips there can be a lot of sticks and debris to remove. (I have learned that even if you buy it, that can still be the case). I just do a gentle raking over the surface, in kind of a herringbone type pattern with a soft leaf rake. (Either water it well first, or wait for a heavy rain. It is so much easier). It allows you to both level the mulch and make piles of sticks and large ‘chips’. Look at the difference it makes.
BEFORE
Jumble of sticks and huge chips… close-up
Very messy garden
DURING Piles to be disposed of
One side done, one to go
AFTER
I do this raking every week or so for about a month and after that I just pick up sticks that pop up to the surface. So easy.