Try to avoid stillborn units\weapons\armors
Almost all Civilization and some global strategy games had one flaw - sometimes new units\chassis\ship hulls become obsolete way too fast.
So players do not bother with building some units and just wait till they get more powerful versions of desired technology. Like ignoring battleships when Dreadnoughts are several turns away. Same goes for weapons - ignoring, for example, Laser II then you could get Laser III after a couple of turns and Laser IV is much much further down the tech tree.
Overall it is better to have less weapons, hulls etc. but make them more important and meaningful. IMO it is better to have five Laser options in total than deal with Laser XVI, Rocket XIII and Mass Driver VII
