Every amp builder has their own take on this, and there is not a single answer. It really depends on what you want your faceplate to look like, and how much you're willing to spend.
I confess that (all) the home brew methods I've tried usually come up short of perfection.
For a demo or experiment type of build, where looks are not important, I have a Brother label maker that works great. I've printed decals that "work" but frankly my crafting skills seem deficient in that department. I've had Fedex print faceplates on fancy paper that I've then laminated, or placed under acrylic. All ok, but . . .
For a project that must be top of the class, FrontPanelExpress is worth the cost -- but boy oh boy have they become more expensive over the past two years it seems.
One thing about FrontPanelExpress is that I now use their "free" software to produce design drawings of chassis cutout templates - it's really accurate.
Since I don't build many stock amps, the pre-made silk-screened face plates rarely work for me, but they can be cost effective and look good. There's a guy in Thailand that sells a lot of them (and chassis's) and folks are happy on the internets with his products --
http://www.solandfa.com/about_us.asp.