Level 40 - the "hour glass" one

Level 54 - the one with tar bubbles dripping down onto single-colored chains with a baby at the end (but you zap the lightning bubble to the side instead of popping the baby bubble directly)

Any tips on how to get 3 stars on these?? I've tried LOTS of times and it seems impossible...

For what it's worth, I've got 3 stars on everything else up to 102, it's just these two levels that are stumping me. (And I've 3 stars on several beyond 102, but I'm still working my way through the upper islands.)

This doesn't have to be all about me though! I figure we can all use this thread to post for help in achieving 3 stars on whatever levels are giving us trouble.