This is how I usually go about doing things, but not all people will agree.
Don't build a district if you still have jobs and housing left. For example, total Pop count is 18, there are 4 jobs available and 2 housings available. Don't build anything just yet. A non-city district gives 2 housing and 2 jobs. When the total Pop count hits 20, you are now left with 0 housing and 2 jobs. That's when you should build a district, but of course that's if you want to focus a planet with certain district (mining, city, agri etc).
If the Pop count is 18 and there are 2 jobs available with 4 housings, you should probably build a specialist building on the slot that unlocks when the Pop hits 20. Because 20 Pops will have 0 jobs available with 2 housings left. I usually build a alloy refinery because it gives 2 more jobs. Now I am left with the even 2 jobs and 2 housing. I don't outright start building specialist buildings because promotions cause sudden drop in income of various raw resources.
However, and I believe this is very important for long term status quo of the planet's stability, if that planet can't grow any further - You should probably want to end up with more HOUSING than JOBS when the planet reaches the point of full development and emigration/unemployment/overcrowding becomes rampant.
Because first of all, overcrowding is the one that causes stability to lower. Increasing housing gives you a bit more time before that overcrowding starts hitting the planet. Nobody really cares about unemployment as long as they live off handouts like social welfare or utopian abundance + plenty of food. Unemployment in this game, you can think of it as excess resource for you to utilize.
Second of all, continuing on that note, you can resettle (even as egalitarian fanatic) more available unemployed workers to other colonies to fill vacant jobs for faster resource gathering and growth.
My capital planet ended up with 142 or so housing and 132 or so jobs. The 10 unemployed people can be dished out to other colonies to fill other urgent worker jobs. (Especially to ecumenopolis they desperately need people to fill all those vacancies.) Now, as long as I have vacant housing and jobs elsewhere, my capital will have plenty of time and enjoy 100% stability. But even that will eventually end if you stop expanding and all of your colonies are fully developed like your capital.
And due to plenty of housing still available, the future-unemployed Pops will grow rather speedily.
If my capital had 132 housing and 142 jobs, 10 jobs would still have to be filled while taking stability hits due to overcrowding. And then you start to get 1... 2... 3... unemployed pops for you to dish out, while still maintaining the hit on the stability. Not only that, they will grow very slow due to overcrowding/emigration and etc.