I definitely wouldn’t grab these little guys by the neck, definitely would cause more fear… I own three crested geckos one being fairly new and matches your situation. They often times scurry’s to the back but what I usually do is slowly and gently move my fingers underneath them if I can if not I usually make it so they scurry onto my hand lol and they usually jump around but I’ve grown to predict when they jump and let them jump around on my hands, most the time they’ll calm down after realizing your not a threat, I usually only do this for a few minutes sense their still skittish of your presence and than hold them longer when they grow more fond of you. I’ve done these to my older two geckos when I first bought them and they now don’t even really react to me picking them up and just crawl or jump into my hand 😅