The most common and most likely answer to this crossword clue is the 8 plus 7 letter word FEMININE ENDINGS
F
E
M
I
N
I
N
E
E
N
D
I
N
G
S
Buddy explains!
The straight part
We know that "Commonality of petite dominatrix and blonde actress" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case commonality of petite dominatrix and blonde actress = feminine endings.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.