I don't know about it being an advanced method, but it will for sure frustrate you and make you wish you were building with glass.
I started building them after I saw one built by Forest Trekker posted here.
Through trial and error (lots of error), and advice from the Gang, I have come up with this:
bamboo backing is 1/8" tapering to 1/16" at the tips. Flatten this piece, cut it to the bow's profile, and then bring it down to it's final thickness and taper.
For the core, 3/16 tapering to 1/16 should get you into the 40+ pound range.
Flatten the belly lam then heat treat it before final flattening and thinning. I use a torch, going over the boo carefully to avoid burning it. You will see steam coming out of the ends and you'll notice that it cups backwards from the heat. I see this as a good thing as I can now get it really flat and thin. Again, 1/8" tapering to 1/16". It can be thinner if you can manage that. I use a jointer and two push pads, but it's still an adventure. A belt sander will work too.
I also prefer a width of 1 3/8" for these bows.
Good luck and post pictures.
Dave.