Generally big bait big birds (Gannets,seagulls,ospreys)Ospreys are great when you cannot see a school of bait watch where they are diving.Mullet make a v-wake when swimming,bunker tend to stay on top and school up and swim in large circles until the tide pushes them in or out at low tide they may be close to the shore reel the plug all the way into the beach or river..Sandeels and spearing are usually pretty visible close to the shore if your using larger plugs and nothins happening try switching to a thin profile hopkins,diamond jig and see if you hook up Charteuse green teaser is a good color.