Maybe this will help: https://www.ballarddesigns.com/howtodecorate/2015/12/whats-the-best-way-to-hang-your-drapery/
These are my no sew curtains: https://www.aratariathome.com/blog/diy-drop-cloth-curtains
The easiest method I have ever seen, was one long length of cloth, draped over curtain tie backs which had been placed in the upper corners of the window frame. The fabric, hung down to the floor on either side and draped in the middle of the top of the window like a valance.
The easiest way is to use a rod with rings and clips. Hope this helps!
Target has a good selection of clips to hang curtains. Just start at the ends fold in half put one in the middle then space them out from there. Stick a rod thru and they are ready to hang.
Not sure if this is easy but I say this post on Hometalk