Loss of Etiquette

Frame preparation is a lost art. So many bikes come straight out of a box, partially assembled, and the shop lubes, checks , and tightens, and *bam* it's a bike. Even though many, probably most, shops do custom builds; a bare frame and a selection of parts, very few have the tools once deemed necessary to properly assemble a bicycle. I am referring to the "facers and chasers", those precision t-handled monstrosities that (hopefully) live in a suitcase of sorts. If you're fortunate, the suitcase is wood and has 'Campagnolo' burned into it. If you are somewhat fortunate, like me, they say 'Park' and you got the box elsewhere.
One tool served the purpose of chasing the bottom bracket threads; making sure they were clean, and cut well. Another cut the faces of the bottom bracket shell to a smooth parallel, and another performed that same function on the head tube.
Some would argue that this is an unnecessary step, that it exposes raw metal; never a good thing, especially on steel. The bare metal is easily solved by a couple coats of lacquer. Unnecessary? Not if you want your headset and bottom bracket to work as designed. In both cases you have two sets of bearings working in tandem at opposite ends of a piece of tubing. Any variation from parallel puts strain on two points in the system, creating drag and wearing those areas unevenly. This equates to more work, less efficiency, and the need to replace parts more often. Systems such as Grease Guard© are designed to last many years longer that sealed systems, yet a slight, uneven pressure can wear down a bearing cup very quickly, destroying the system.
I admit that I am fortunate to have access to these tools. It's why I build my own toys. But shops have access to these tools, also, and while they are expensive initially, the added degree of mastery to your final product will more than justify the expense.