Tactical RPGs have come along way from a flat 2d landscape with a hit dice and RGB effects or arrow sprite. Of course, they are mostly still revolving around the merits and malus of the character, with some influence from the tool employed (e.g. bow and arrow) and little from the environment, (e.g. a wall if good pathfinding has been programmed).
Therefore to find a new tactical initiative, it would seem we need to examine the characters. The easiest characters to observe are the magical characters, as they have the widest range of abilities, as they are magic ('no der!'). So I suggest some form of team, action point. For example, should your Cleric choose the spell 'hold person', and select it as a team action, for this round it will not be a time/round enduring action, but a single action. A wizard may then choose a 'raise into air spell' and an archer a 'gonad shot!?', once all these selection are made, a play action choice is selected, and the scenario plays out.
Of course the question was to make things more tactical, now this may require some initiatives to be conducted at height, distance or certain rotation from another character or enemy, this will create a basis for encouraging the player to explore his environment.
