Playing in haste often makes waste!
Once you have chosen a piece to play, don't just play it any old way that comes to mind.
Carefully consider how turning it might be better.
This Yellow Y is an example of an extremely common mistake with the Y piece - the ``nub" is facing the wrong way.
For one thing, the nub in it's current position doesn't restrict Red at all, Red already can't play where the nub is, because it borders the Red Z, but it does cut down on Green possibilities (even if Green has already decided the X will go in the obvious spot, sometimes the opponent surprises us and plans change, so more flexibility can't hurt).
For another thing, there is now an i4-leak that Red can play in on the right side of the Yellow Y, either now, or later.
Finally, Yellow has only one new corner created by this Y, and it's kind of far away from it's next closest corner at the top of the Y.
Putting the Yellow Nub on the other side as seen here:
is a much better choice.
This move leaves more options for Green on the left side of the Yellow Y, but no more moves for Red, it doesn't have any leaks for Red, it makes it hard for Red to move up the right side of the board, and gives Yellow 2 additional corners.
This move is better in every way.