I would think a lot of us DIYers have woodworking tools and experience but your right, its only cost effective if you already have pretty much all the equipment. And also correct on having the skill to make it look as good as pre-made ones, although I have seen stands made completely out of MDF without any fancy routered edges (might have had 45* bevel just from the saw) that was painted black that looked very nice contemporary look for cheap.
Woodworking tools I used for stand/canopy:
-Sliding miter saw (but there are cheaper saws that will work)
-Table saw (for making longer cuts than the miter can)
-Air nailer & air stapler (could have done it all with screws and drill/screwdrive but the air nailer makes it go quicker)
-Drill (with bits for drilling, screwing, and countersinking)
-Misc clamps: pipe clamps, bar clamps, c-clamps
-Measuring stuff: tapes, rulers, squares
-and of course your hardware, and finishing supplies
Thats the majority of stuff i can think of off hand, I am sure there were more tools utilized... projects seem to always need stuff you dont have or cant find
Note: dont expect to make a nice looking stand for a 4' tank out of cherry or walnut or some fancy hardwood for cheap. When your using hardwoods your mostly paying for the wood and probably will run you a couple hundred or so for all the wood for something like a 75G. I like the country look of just pine and the cost savings, so far thats all I used for my larger projects, but maybe someday some nice curly maple, or chery with walnut inlays...