All of the games you mentioned regularly destroy my characters and plans, but that's part of the fun of them I think. Dwarf Fortress is one I haven't put enough time into due to the sheer depth and confusion of learning everything, I do plan to revisit it when I've got the itch for a colony builder and want to fail horrifically.

For Caves of Qud and Tales, my best recommendation is to try out new things and builds and see what works. I had miserable luck in Caves with most of my melee focused builds, but using a ranged focused build (use your ammo semi sparingly until Grit Gate where you can buy 1k rounds per restock) was what got me further then ever before. There's some abilities that help immensely with survival too, the Precognition mutation allows you to see the future and reset on a cooldown, even if you stumble into an unfortunate death for example. Also look at domination or proselytize/beguiling, as those will allow you to recruit or control other characters, even shopkeepers who you can then drop the full inventory on the ground for you to utilize (though be careful, failure may turn them against you). Using a zone tier map like the one found on the Qud wiki if you don't mind knowing roughly how tough each over world area is also is a good way to avoid stumbling into an area you're not prepared for.

Tome I have less advice for even after 100+ hours, I had a blast trying out all sorts of build combos, but a good way to get an idea of what builds work well is to check out https://te4.org/characters-vault and search for your difficulty and campaign, and filter it to only show winners. This will show you a list of characters who have cleared the game, and allow you to see what their exact build was upon winning, including stats, talent choices, gear, and a few other useful things. Having a zone order guide pulled up absolutely helps as well and is a decent way to get familiar with where to go when still starting out, especially if you want to see every zone the game has to offer.

Lastly, for Qud, ToME, and even Dredmor, don't be afraid to turn on a difficulty that isn't permadeath. I love the thought of only having one life, but for learning the game it's never a bad thing to turn that off for your first run (or first few!), as it'll allow you to retry the same scenarios with different approaches to see what works best. Qud I think does this the best with it's Roleplay mode, checkpointing at settlements so you're set back usually by dying, but you can still continue on to get a better understanding of all the game has to offer, making future runs that much smoother. Death is all part of the fun either way, sometimes you've taken a character to the point where it's starting to feel stale and a new build can reinvigorate interest in wanting to continue exploring what the worlds have to offer!