Herring (Tommy Rough) are a small aggressive fish. Many people traditionally use burley up and use bait to catch these tasty little fish.
However, if you want to focus more on Herring and avoid by catch. Try using a green straw lure. This is probably the cheapest lure you will ever find.
Top spots are normally over reefy or weedy grounds up to 6 meters in depth. Burley is the key to getting some herring. Anything from bread crumbs (can be enhanced with tuna oil) to speciality store bought burley, not the pellet type, will do the trick.
It often pays to be patient as you might attract some less desirable species at first, but herring are aggressive and will tend to beat most undesirable species once they are in the mix.