How I do it is I go on gdax.com and log in with the same credentials as coinbase because it’s the same company. Then I go to the accounts and go to the section that has coinbase as one of my accounts. I choose the currency that I purchased and I transfer it over with zero fees. From there I can send coins to any platform I choose without any charges.
I did my research and I found this method because it wasn’t very pleasant to send 30 dollars and only receive 15 on the other end. I hope this helps.
If you want 10 dollars for free when you purchase your first 100 dollars or more on coinbase. Sign up through my link.
Have a wonderful night.