We have strong tides here and in places there are 500-800 meters of beach between the high water mark and the low tide line, how do you go about working a beach this size?
Always start off by observing where most people are, there are multiple zones to a beach. See were people congregate the most at the beach both high and low tides.
The first time I went to the beach it was overwelming I looked for low spots or sloping areas did ok but was glad to get back to my fresh water beaches good luck
Having gotten use to Florida beach hunting, and now seeing "Nova Scotia" under your avatar, the first thing I'd do is invest in some warm gear and build a nice warm fire pit. Heck, I'm getting chilled just looking at the picture and thinking about it.
But seriously (I was serious before) given I had the time I'd learn all I can about the beach, it's history etc., then I'd seek out those areas that I felt presented the best possibilities and then I'd pick out a few different features within those locations, i.e., low spots, runnels, troughs, washes, etc. and then I'd select a small area of each and hunt them in a real tight grid until I found something that started paying off. Large expanses of beach can be too overwhelming when you keep your focus on the entire expanse of beach. Pick the best possible locations, then the best possible features, and spend a little time hunting a bit of all of them until you find out what produces for you.