- Lifting weights alone at home (lying down) and letting them fall on your neck and strangle you. Obviously a slow and painful death but exercise at home is very common and most people don't use a spotter due to overconfidence or complacency. Saw a video of a guy who died this way, he rolled the weights the wrong way and it landed on his neck and strangled him on livestream. Also had narrow misses of people who almost died this way when they didn't have a spotter, the gym was almost empty, and the other patrons were in the bathroom, occupied, etc.
- Walking into traffic while distracted texting/being on the phone, or "making a mistake" while cycling. I don't recommend this because it's bringing someone else into your suicide, but it's a pretty plausible scenario because these days fuckers are always on their damn phone. Just make sure to not make it seem obvious you're targeting any vehicle, try to play up a look of shock or surprise if possible.
- Drug overdose, as mentioned, however this will probably be suspicious if you aren't already a regular user and depending on your network, it could be hard to locate a dealer.
- Doing electrical work at home without turning off the power. Quite a few people die annually from not trusting an electrician but being too much of an amateur to do the work themselves. In a similar vein, "accidentally" having a failure with a car jack while working underneath a car.
- "Accidentally" starting a house fire (letting a cigarette or candle fall, etc.) while heavily imbibed from drinking, sleeping pills, or drug use, possibly asleep at the time. Hell, a house caught fire a couple of blocks away just because they never cleaned out the lint trap.
- What I call "TikTok deaths," though they've long preceded the service and are just generally associated with risk-taking lifestyles. Countless people have died by hiking or skiing in off-limits areas, so why not make it work for you? Accidentally take that extra step back off of a steep cliff while trying to get a good selfie, or stand on a precarious cliffside boulder for the 'gram, find some malfunction with your SCUBA gear while diving in a restricted area, pull your parachute a little too late while BASE jumping. Unfortunately you might traumatize some onlookers or just paralyze yourself so make sure you run your calculations.
- Decide on a career change and get to work in any kind of factory that uses heavy machinery you can get too complacent around. Works best if you live in China, Russia, or India.
Note that none of these are guaranteed, painless, or instantaneous methods, and they weren't intended to be while I make the suggestion... Simply deaths I've seen or heard about that could be replicated on purpose and look like an accident.