I ditched crush washers and peel washers years ago in favor of shims. Crush washers are too easy to install slightly crooked (which is the reason many suppressor manufacturers warn against them for suppressor mounts) and peel washers are just a pain to deal with. Shims, like the new ones from White Sound Defense, go a long way toward ensuring a straight muzzle device install and are very easy to deal with.
The White Sound Defense 5.56 Muzzle Device Shim Kits are unique in that they have a slight cone shape which helps naturally align the entire stack of shims. Each one adjusts the orientation of the muzzle device by about 1/8th of a turn. This has a natural torque setting effect, allowing you to stack your washers until you are within 1/8th a turn of the desired orientation when hand tight and then tighten with a wrench to proper alignment and torque.