No doubt a shop-quality workstand is the best thing to hold your bike while you work on it. If you can afford one and have a place for it, buy it. Consumer workstands can be almost as good or really miserably bad. If you can see the stand and push it around before you buy it you can see how stable it is and examine the clamp. On a stable base, get a clamp as close to the pro model as you can.
Short of a solid work stand you can simply hang the bike by a loop of cord from a door frame. The bike will sway around as you turn the pedals or reef on tight threads, but it’s better than nothing. If you have to hang the bike like that, do your heavy yanking with the bike on the ground and only hang it to adjust gears or do rough wheel truing through the brakes.