Level 74 needs (almost) all the potions you have!

Starting Bubbles: 50
Recommended Magic Potions: Golden Spiders, 7 Extra Bubbles, 3 Extra Ceilings in the hole
Score needed for 1, 2, 3 Stars: 
60 000, 90 000, 120 000
Special Bubbles:
Infected Bubble Infected Bubbles,
black bubble-is-hard-as-rock Black Bubbles

The special design of level 74 makes it very challenging. There are infected bubbles on both sides, just between the wall and a column of 8 black bubbles. The columns of black bubbles assure you to have it hard, because it makes the playing ground so much smaller at the end. As it wouldn’t be enough, you have to watch out not for the infected bubbles not to get lower than the black bubble columns. If the infected bubbles get lower, they prevent you from seeing the ceiling, leaving you in the blind.

A screen cap (as explained in post about level 55) could help you see the ceiling, but it is very challenging to take the cap at the exact right moment to get the ceiling row on it.

Good luck to you! (You will need it!)