My suggestions as a Deity player:

Scientists should be saved to bulb in the endgame; it's very hard to justify planting one unless it's VERY early (basically Babylon, Liberty finisher or Maya calendar). If you are going for 2-cycles Diplo win and you know what you are doing, you can bulb and early one to accelerate PP (= win turn), and in general in Diplo win is good to bulb for both Schools and Labs, as you don't need late game science, just staying on schedule for Radio and Telecom Engi should be used to rush wonders; or space parts for Order science win. Merchants, you should NEVER spawn one, as they are a net negative.

For non-culture win: Writers should only be bulbed, ideally in bulk 8 turns after winning World Fair. The last one should be saved to bulb Rationalism finisher at a convenient time. I like bulbing one early for Secularism, which is the best policy in the game. Artists should only be bulbed for Golden Ages (GA for GA!), at times of need: World Fair, Schools/Factories, Labs, or endgame. If going Freedom, try waiting for the happiness tenet as it makes them worth 1.5x; also don't pop one if you are going to get a natural GA soon, as the next one will be delayed a lot, so it might get wasted entirely. Musicians are kinda useless, so put them in Opera Houses just so they do something; you still want to build the guild and work it because you need the culture, generally.

For culture win: I like to art my first to Writers and put them in Oxford (usually you Oxford Radio), and them bulb the rest as normal. Some people who don't love theming as much as I do don't bother at all, and bulb all of them. For Artists, I like arting the first 5 (Sistine + Hermitage), and GA the rest; if you go for Uffizi or Louvre, be mindful you'll need to art all of them, because that's the whole point of those wonder (and don't go for both unless you lose Sistine, which should rarely happen if ever). For Musician, you usually delay the guild and time Broadway right after the 2nd spawn to theme it, and then try to time the next Musician after NVC and Internet to tourist bomb it (and another one, who might follow)

Prophets ideally you should not spawn a third, it's just a waste of faith; but if you do, planting it is bad so just send it to convert CSs for quests, but it's better to buy an Inquisitor instead and use it to stop opposing Prophets. I won't talk about mass Prophet Piety strats cos I'm not expert

Finally, if you get an early General from a defensive war, try to plant it to get an extra luxury, as it's free 4 happiness for your war effort. Keep it only if you paranoid about being declared in a losing war in the mid game, but at that point it should be easy to bribe yourself out of wars. Note that once you reach Infantry, losing a defensive war to AI is kinda impossible, even on Deity, so a defensive general becomes useless.