Not difficult and there are many ways of going about it. I happened to have an unused 4foot 75gal metal stand, and I needed a stand for a 6 foot acrylic 110g tank, and some wood laying around. The result is quite solid and practical.
would it be a good idea to add a extra amount of biomedia, such as rolled up sponge pads?
its kind of tempting to use sponge pads in place of a substrate, lots of surface area that way