In order to get 5 star completions for every act, you need to perform high combos and have your mood meter at level 4 on a consistent basis.
The best way to go about this is to use parry + flurry attacks (circle + square, square, square, square). If possible, equip the werewolf and scarab shell charms to boost your mood meter quicker and lose less when taking damage from an enemy, respectively.
Tips: when holding an enemy in parry and there are multiple enemies around, wait a moment to allow other enemies to get in range when you start to use flurry, this will hit all enemies in range to boost combo and meter dramatically.
It is more important to have level 4 mood meter than having a high combo. Do not get greedy and attack just to keep combo streak alive ,especially around big enemies or range hitters that can easily set you down a whole level if they land a hit.
When facing groups with big enemies, I suggest parry + flurry + toss (circle, square, square, square, circle) towards the big enemy. This will daze them and you can then grab and flurry with them as you would a normal enemy. This also helps limit the chances of a big enemy disrupting your attacks.
When facing bosses and mini bosses, be sure to kill all other enemies before killing the bosses.