I usually do long tail cast on. Depending on yarn and needle size and attitude it can be very tight.
you could try by knitting magic loop on circular needles. Or knitting on 2 cirular needles if you have (Cat Bordhi).
you can also try an (almost) invisible cast on that I found under "magic loop cast on" (careful there is something like this for crochet, too.). But I can not find the video right now. Once I find it, I will update here.
I did however find this video:
I just noticed that her 2nd method is what I wanted to show but the first one is awesome, too. Good that I found this video.
If need be I make a demonstration but I am surely not as good as the original instruction.
A written instruction you can find in my Frog Prince Pattern