As always, Amethyst's advice is excellent.
I got my first chin recently (a little over a month ago), and I've found that patience is one of the most vital virtues to exercise when trying to bond with a new chin. You kind of have to put aside your own hopes and expectations (and ego) and take your cues from the chin. Go at his pace and let him come to you rather than trying to force your love on him right away. Once he's settled in a bit and seems comfortable in his cage, you can start talking to him, giving him some goodies (just be careful not to overdo it with the treats, you can offer things like bits of hay, pellets, chew toys, etc. on non-treat days, or as a total replacement for treats if he's a baby), stuff like that. When he seems ready, you can open up the cage door and just put one of your hands in there while you talk to him. Let him come up to you on his own terms and sniff you and check you out. You can try to gently pet him, but if he startles and runs away, don't try to chase him around the cage and force more pets. Let him escape and come back to you on his own time.
I found that in the beginning, my chin readily accepted being touched around her head and neck area within a couple days, but really didn't like being touched on her back or haunches (now she'll let me pet her whole body, but it took some time). I don't know if that's typical of chins generally or if it was just a quirk of my specific chin, but if your guy repeatedly startles and runs away when you try to touch one part of his body, then perhaps try touching a different part of him next time. It seems like most chins love being gently scratched under the chin (mine also loves it behind her ears), so that might be a good place to start once he's settled in a bit and will come up to your hand when you put it in his cage.
The other thing I've found to be really important is consistency. Once he's settled in and you've started interacting with him, it's really helpful to interact with him every day, ideally for an hour or more. You don't have to take him out of the cage (in fact, you really shouldn't take him out if he's a baby, and even if he's an adult, you should establish a bond before you start letting him out). But just talk to him, pet him, scratch him, let him climb on your hands, etc. If he'll let you, you can pick him up and hold him for a bit (but don't force it on him if he's not into it, unless you really HAVE to pick him up).
So yeah, basically just take it slow, be patient, be consistent, and take your cues from your fluffball. If you notice him starting to get fearful or stressed, back off and give him some space and time to calm down. Always remember that a chin's natural instincts will be telling them that we as humans are large and scary predators to be feared. You're trying to teach your chin to overcome that instinctual fear by showing him that not only are you not going to kill him and eat him, but that good things come from you.