I have a bit different approach. First, in agreement with other members, regular maintenance must involve water changes, no less than once each week (on the same day is best). I do close to 60% or sometimes more. Provided the water parameters of tap water and tank water are basically similar--and the point of doing water changes is to ensure they remain similar--this is extremely beneficial. [This is why going down the road of having to adjust your source water is such a risk.] During the water change, I clean the inside of the front glass with a sponge-type scraper, or an actual sponge by hand. I rarely if ever see anything on the glass, but I do this regardless; surfaces under water develop a biofilm rapidly, and microscopic critters and algae adhere to this. If ignored this can sometimes be harder to remove--green spot algae for example--so weekly cleaning means clear front glass and if you happen to forget one week, no problem. Think of this as prevention, not reaction to a problem.
I rarely touch the substrate. I do clean the sand in my smallest tank which has my spawning pygmy cories, but the other tanks are not touched (they all have play sand). I never dig under wood or rock except when I tear down a tank. The anaerobic spots are as important as aerobic areas (which will be naturally maintained by plant roots, snails, some fish, and not overfeeding or overstocking). But not having too deep a substrate tends to eliminate most problems before they occur--another case of prevention not reaction. The substrate is the most important component of an aquarium, more than the filter. You can (or should be able to) do without a filter, but not without a healthy substrate.
Filter. On my two largest tanks with a canister, I rinse the media under the tap every 6-8 weeks. I used to let this go for months, with no issues; but for reasons I won't get into now, got on to this 6-8 week schedule. The main thing is, you want the flow from the filter to remain steady, and this means ensuring the organics (the brown muck) in the filter and which accumulates in the filter tubes is rinsed out. I have seen the flow significantly decrease from buildup of the organics in the filter return hose.
On my smaller tanks I have sponge filters, and one has a small internal filter that is nothing more than foam and a motor. I rinse these at every water change without fail. I probably don't need to, but it doesn't hurt, and it is a good habit to get into.
The prime job of a filter is water circulation and mechanical filtration, which is the removal of particulate matter (often microscopic) so the water remains clear. Clear and clean are two different things, and here we are talking clear. As for clean, that involves biological filtration, and most of this will (or should) occur in the substrate. Obviously biological filtration will occur in any filter basically, but you should not regard this as its primary purpose.
The above is all the maintenance my tanks get, over years. I guess the longest I have had a tank in operation from set-up is five maybe six years. Most times I set up a tank, and I might decide to move those fish to a larger (or smaller) tank and do something different, or I changed the substrate from fine gravel to sand tank by tank, or when I moved. Once a tank is established--which is a very different thing from cycled--you really do not want to be messing with it beyond the water changes and filter rinsing. A balanced biological system will ensure more stable water parameters, water conditions, and fish health, so leave it alone aside from the regular maintenance.
