Best Practice For Waiting Between Multiple Functions?

In one of my scripts I want to wait 1 second before doing something, 5 seconds before another, 15 seconds before another, and renderstep a 4th.

Would best practice be to renderstep the one function, and then spawn() another function to its own thread such that it waits 1 second every time and when timesRun % 5 call the 2nd when timesRun % 15 call the 3rd? Or should I do all of that in a single renderstep? Or (and I'm not familiar with this) can I somehow utilize coroutines in here to remove the spawn()?

I am able to do any of these options, I'm just looking for a best practice to minimize cpu utilization because these are going to be running/yielding constantly. Thank you for any help.