Double Cluching

[1928Pickuppain]

So Im having a hell of a time double cluching. Everytime I try to shift i get grind grind. She goes into first fine, goes into reverce fine; but up shifting or down shifting it grinds i dont know how many Rpms i need to get it to to double cluch. I understand that i cluch put in neutral, rev engen, then cluch and put in gear is there any thing I am doing wrong is there a secret to it? I just got the old girl registerd yesterday and am trying to figurre it out without breaking her.