[AS2]Horizontal Shmup Help - Enemy Patterns

Hey guys, I’ve just been playing around with some horizontal shmup style stuff and wanted to give my enemies a little more depth. In games like R-Type and Arrow Flash, the enemies have waves and patterns. I thought about it for a while and I’m kind of just left wondering.

So how would you do it?

I thought about having a timer on each enemy that just triggers movement in different directions after a certain time has passed, but I can’t simulate cool stuff like enemies spinning in circles or waving up and down the screen if I do it like that.

Any help or input is greatly appreciated!