i think it's finally time that you add some SFX
not simply for the "juice" factor, but most importantly because they are fundamental feedback to let players know that a button was successfully pressed, a ship design was saved, a research is started, a research is completed, a probe is in orbit etc
aside from that, occasionally i have add UI elements covering the dialog screen, or character portraits covering buttons to press. ideally, things that are of utmost importance to the player to know (buttons, dialogue etc) should always be in foreground compared to more background elements for flavour.