If you are anything like me, you will find the easiest/low hassle way of getting things done. I found this tip from an Instagramer I follow (Frills and Drills) and I finally got the chance to try it out. It worked like a charm!
I did it using this adhesive hem tape (click on the link):
Figure out how long you want your curtains to be and pin it in place.
Use an iron to make a hem line. This will make it easier for the next couple of steps!
Cut the curtain about 1/2" below your "hem line".
Now for the magic. Apply the adhesive hem tape right along your hem line and fold over the extra fabric. Once you do that, iron the hem line to activate the adhesive in the hem tape. Be very careful not to get the hem tape touching the iron directly. Set your iron to the appropriate heat based on your curtain fabric and continue to iron until you cannot separate the fabric. I recommend repeating this step to get a nice clean hem line.