I've found that you have to cut the decals REALLY close to the actual image portion of the decal, then in the case of the ultramarines, i cut out a V or |_| shape in the center of the

to get it to bend properly around a shoulder pad. Apply some decal solution to the surface, then on the decal. Let it dry for a bit, then apply some decal solvent to flatten it out once the solution has dried. Dry it off and press it flat with a paper towel/tissue and its good to go.
I'll take some parting pics of my work that I currently have completed before I put it away. Some bonus pics tomorrow(Sunday 27APR2013) as well