In late 1996/early 1997 I found myself working at a practical special effects shop in North Hollywood, California, doing mostly menial tasks on various props and costumes for this and that, but also learning the trade and demonstrating enough of a knack for it that I was put on some builds. By far the most noteworthy one I worked on was this target robot suit for Star Trek: Deep Space Nine Season 5, episode 18, Business as Usual.
I worked under the supervision of the designer and from what I remember, fabricated most of the base armor pieces and did a fair amount of detail work as well, with the designer putting on final touches.
I missed the episode when it originally aired and finally saw it all these years later, now that I'm finally watching the series from start to end. Like so many effects projects that you spend weeks of your life working on, it is visible for about one second in the final episode: