just be creative and use your mind. also like put gears and knobs and stuff any thing!!!
Define 'Competition' and I can answer this.
If you say you make steampunk stuff, it's not exactly one-off and rarely a competition. Sure, there are those looking up to others, and others still that do spin-offs, but even me, a mere newbie stepping up to the plate to finish off an old rifle of mine (shoots airsoft ammo) is trying it.
If you mean that you make steampunk stuff for competitions, I still can't exactly answer it. The reason: I don't make stuff for competitions. My fun is done in the building process. I like messing with hacksaws, screwdrivers, assorted plumbing parts, a scrap of wood or 2, some paint, and a tub of 5 minute epoxy. (I warn you, if you use epoxy, don't get the hardener on one finger, resin on the other, and stick them together. A friend of mine did that earlier with my 5-minute stuff and had to go to the hospital cause we couldn't unstick them without breaking his fingers. I offered him the 'easy way out' and told him, "I have a bar clamp that says I can have your fingers apart in 30 seconds, but it'll hurt" He took the smarter way)
Excusing my long post here, my point is that steampunk items, and cyberpunk, for that matter, and any other of the items forgotten to be mentioned here, they're not exactly a rarity.
Need proof? Key in Steampunk into the Instructables search bar and have a little fun looking at stuff for inspiration.