We've lived in our current flat for 4 years and 9 months. But the longest lease we were ever allowed to sign was 12 months. And since 2010, our employment/living situation has been a bit uncertain. So since we moved in, in 2007, we've always thought we would move out sort of soon. As a result, we avoided the sort of regular cleaning that you might do if you knew you were staying a while - why clean now, when we'll just have to do it at the end of our lease? I don't mean that we lived in a dump-hole. Our house was regularly tidy, and I always kept kitchen, bathroom, and living areas clean. I'm talking about the less-necessary cleaning -- getting dirt out of window tracks, cleaning windows, getting oil spots off garage floors...
Well, now we're at the end of our lease, and we had about 5 years of built-up dirt to clean up. We're fairly unwilling to spend money on cleaning products, though, especially since most are pretty terrible for health and the environment. But we do have a few nearly-empty bottles of things, and our natural cleaning products. And with these, plus a lot of elbow grease, we've been able to get everything pretty clean.
Vertical Blinds. Ours are vinyl, and were pretty dusty and a bit mouldy. We took each vinyl strip down, removed the plastic inserts, and soaked them in boiling water with a tiny bit of bleach (we got half a bottle of laundry bleach with a second-hand washing machine we bought once). When the water cooled, we scrubbed them with a sponge and then hung outside to dry. They look like new!
Curtains. These were already very faded, but had some water & dirt marks from open windows. We took them down and hand washed in some hot water and laundry detergent, and then carefully hung out to dry without getting wrinkles. They're still faded, and the stains didn't disappear, but it's good enough for us.
Oil spots. Luckily, there were some oil spots on the garage floor when we moved in, so the ones from Andy's car don't stand out so much. But, there was an obvious distinction between old and new oil spots. We had a bottle of floor cleaner (from god knows where) which claimed to cut through grease and grime. I squirted that onto the spots and scrubbed (and scrubbed) with a stiff brush. After rinsing and drying, all the spots look old and some are barely visible.
Carpet stains. We only had one - a cat puke stain, from when Nacho ate a shoelace, and we were a bit too busy and preoccupied to clean the carpet properly. I got this up with just a bit of bicarb soda and vinegar. First, I made a paste of bicarb soda and water, and scrubbed that into the carpet with a brush. Then we sprayed with vinegar water and let it fizz up. Blot with paper (or rags) and let dry over night. In the morning, it had dried and was a bit crusty, so I just used a dry brush to break up the crust, and then vacuumed. Be warned, though, that this will leave a clean spot in the middle of an otherwise kind of dingy carpet.
General cleaning. I made a mix of dish soap, vinegar, clove oil, and eucalyptus oil, and that has been a really effective all-purpose cleaner. This is going to be my go-to cleaning product from now on, I think. It cuts through soap scum in the shower, kills mould (from the clove oil), and disinfects (from the eucalyptus oil). Spray it on, let it sit a minute, and then wipe or scrub (depending on how dirty!). Leaves bathrooms shiny as, and gets regular smudginess of painted walls and doors.
Windows. This is hardly original, but vinegar + water sprayed on glass, and then wiped until perfectly dry with newspaper gets windows crystal clear. I do it with one wet newspaper, one dry newspaper, for maximum efficiency.
Outside tiles. Our pavers were covered with something green - moss? algae? I don't know what. But it happens every wet season, and our real estate has been cranky about it before. So we've gotten good at this one - all it takes is scrubbing. With a stiff brush. Scrubbing, scrubbing, scrubbing, and then washing the dirty residue away with water.
Kitchen bench top. Our counter top gets a bit dingy, so every few months (and especially now) I clear everything off of it, sprinkle dry bicarb soda all over, and scrub it in with a damp sponge. Pay particular attention to any stains (around our tea pot is a bad spot, and near the stove where turmeric-stained spoons get set on the counter). After it's all been scrubbed hard, spritz with vinegar, and then rinse off.
A few more things... Those gimmicky "magic erasers" work only sometimes, but where they were really effective for us was on greasy things - the inside of the oven-window, the top of the cabinet above the stove (which was surprisingly grotty!). Andy's parents washed down the walls, using a mop, with sugar soap, and then washed it off with methylated spirits + water. This made the walls look really good. Some bits of wall had caked on sticky tape - WD40 and a scour-y microfibre cloth got rid of this. Window tracks came clean with a rag stuffed down into the track with a pen cap.
Basically, it was mostly elbow grease and natural products, with a few chemical-y things thrown in that got our place sparkle-arkly.