I want to know good code for making animations smooth and what would be a good time to wait for it to swap to the next frame.

How about:

define animate (frames) frames with delay (delay)
repeat (frames)
next costume
wait (delay) secs
end

when flag clicked // Sample code, adjust to your needs
switch costume to [frame 1 v]
animate [10] frames with delay [0.1]
wait [1] secs
animate [5] frames with delay [0.2]
...

I think a good delay time would be anything less than like 0.3 seconds depending on how many frames you want to make
I don't know much about animation so I don't really know, but hope this helps anyway lol

Appreciate it!
I like the Silently scream thing