Patients is the key word. They will settle down when they feel comfortable with their new situation. If holding them is still an issue I wouldn't push it. Settle for them crawling through your hand while they're in their enclosure. Let them come to you. Their natural curiosity will bring them out. Offering food by hand is a good way to get them more comfortable with you. Hunger is a great motivator and will win over fear most of the time. I have wild radixes that trust me enough to come out and grab a worm from me but they won't let me hold them.
Some snakes take longer than others and some snakes never loose that startle to humans. Be calm and patient and it should work out.
Keep us posted on your progress.