A few tips on scoring big:
#1 Be patient; you'll lost time, grip and points grabbing thorns. Way more than just waiting until you're sure you've got the right flower.
#2 You only need to grab the white flowers to get three stars, but if you're losing grip you can hit up the green, coin and bomb flowers to buy more time.
#3 If you don't quite have the knack, practice. I can deflower (teehee) the twenty hardest spirits now faster than I could deflower just the tenth easiest.
#4 If you're not quite there, don't worry. Improving your grip with glove upgrades from Mr Shopkeer and personal attributes from Trainer will give you more time.