Higher surf and rising tides mean more sand stirred up to expose more forage and new shore being churned up as the tide rises. If surf is too big, they don't want to be thrashed so they'll slide out a bit deeper. When it's small, they are more skittish in the cleaner water, quickly swimming into the rip clouds to quickly eat and then exit. When it's small surf, look for any deeper troughs like where rip currents are washing back out--you don't need much of one to find fish in or next to it. Be mobile, if one doesn't have fish, go down the beach to the next. You may only pluck one or two from each in those conditions.