How old is your bird? If he's less than a year old, then the only way to tell is by having a DNA test done. If he's over a year old and has no ring around his neck, then he's a female, but if he develops a ring then he's a male...But if he's still a baby, then it's far too young to tell just by looking at him. Those other methods you mentioned are not at all accurate, but rather "myths". The only way to know for sure on a Ringneck that is under a year old is by having your Avian Vet do a DNA test, or you can actually order a DNA kit online from several labs, you pay them and they send you a testing kit, where you simply send them back a few of your bird's feathers, and then they do the DNA test for you, and you'll get the results in a couple of weeks...