How do I enjoy people's forms without desiring them or becoming attached and thus kept from appreciating their true Being beyond form? There's a person who I find physically attractive & I find myself Desiring them, but since they are a stranger it often leads to lust and suffering. Doesn't spirituality teach that Forms transition/wither and lusting after people's Forms is limiting and even harmful to both parties? How can I just focus on that person's Being to enter the recognition of Oneness?
What is harmful is believing yourself to be defined by and limited to your own body. Then you see others as being defined by their bodies.
Accept your own body/form by inhabiting it deeply. In doing so, you will actually pass beyond form into that which some have called formlessness. That is the somatic meditation work taught by people such as Reginald Ray or Judith Blackstone. I highly recommend their books.
When you discover your own existence without relying on form, you will no longer see other people in those terms either.
Desire shifts and instead becomes Passion. You can still feel strongly toward other forms and enjoy them. But you do not confuse them with being the source of happiness, wholeness, or fulfillment. That is within you, as you.
Instead it is more like a celebration between temporary forms.
You will experience the truth heralded in the Ashtavakra Gita:
I am the unbounded deep In whom all living things Naturally arise, Rush against each other playfully, And then subside.