Iron Hands has an illustrated article on making trench systems for your 25mm – 28mm miniature wargames. The principal ingredients are concrete patch, rocks and fiberboard.
world war One
Battle of Jutland Quick Play Rules
Matt Fritz has written a set of quick play rules called Day of the Dreadnaughts for recreating the Battle of Jutland. The set includes links to paper models, in case you want to try it, but don’t hvae the appropriate miniatures.