here are some of my tips:
keep important building materials on hand at all times. IE: 1/4" glass, acrylic, silicone, PVC piping & elbos, egg crate, etc. You never know when inspiration might hit
Oh, and PVC piping can do neat things if you cut it lengthwise to make original things. I made a "reflector" for a cold cathode moonlight by cutting a piece of 3/4" PVC down the length in half, then supergluing a piece of aluminum foil to the inside. Saw somone use this idea for making a metal halide hood, actually (out of 2 foot PVC)
When starting up a reef, don't be daunted by the cost of larger tanks. Doller per gallon, larger tanks are cheaper than smaller tanks. Just get the biggest tank you can for your space, because equipment for larger tanks is not much more than smaller tanks. A metal halide ballast is usually the same price, whether it's 150W or 250W, the heaters are only 10% more for the larger versions, and the pumps are almost the exact same price. The only scaling cost is the tank the liverock, and possibly the skimmer, which isn't much really.
Oh, and don't turn your tank into a fruitstand. Being an artist myself, I visually despise people who buy 1.8 lbs of liverock per gallon, and pile it against the back of their aquarium, and then display their corals rising up their rock structure laid out like a fruitstand selling goods. It's not aesthetic, doesn't look like the real reef (there's NEVER that much assortment in a 4 foot area), and it's bad for flow.