Once upon a time I would only choose mining stocks, like copper, iron ore, energy, lithium.
Most of these are correlated to a degree, there would be times I could sit for weeks without buying.
Also, when mining turned up, I would hit several stocks simultaneously with large size, this a type compensation for being flat for so long.
I became uncomfortable with that method.
Now I'll trade nearly anything that moves with a few exceptions and not only is it more interesting, but it feels better, safer, and has improved returns.