This is my general build for bats. I route my 4lb, but if I weren't using it I would barber pole the base layer, and then do full wraps on the next two. If you're not using a 4lb biscuit, I don't know if you can get away with only 1 blue cap over the core, as I have shown here. YMMV.
Apologies for the low resolution. Build is as follows (from the core):
core w/biscuits --> wrap of blue foam (or 4lb box) --> cap of blue foam --> wrap of blue foam --> wrap of blue foam --> marine foam cap. Taping not shown.
I've only tried this on smaller blue weapons, so more padding may be necessary depending on the size; I'll be trying it out on a longer blue when I have the time.
Build tip: Be very careful not to compress the foam when you apply it. Pulling on the foam as you apply will compress it, and make it hit harder. I've failed brand new bats with more layers of foam than this, because the foamsmith was careless during the build process.