So I have a run of road frames on the board. Ten in a row. That’s a good time. One is a titanium carbon blend, five are titanium and four are steel. I have no preference over which material to build with although I find the super thin, hard steels to be the most challenging technique wise. Framebuilding, like any fabrication can be broken into two areas, technique and process. Simply explained, process is how things are done. What you do, the order you do them in and the tools you use. Process is very objective and can be documented and taught quite easily. Technique is another thing altogether.
Techniques is what really separates the top builders from the rest when it comes to fabrication skills. Technique takes experience and there is no substitute for experience. Experience isn’t measured in years, it’s measured in units. You can be a framebuilder for 20 years but if you only build 15 frames per year you won’t have much experience. Not only do you need to build units to develop experience and technique. You need to build units repeatedly, one after the other so you don’t forget what you learned on the last unit before you start the next. Technique shows up most in two areas. Joining and alignment. TIG seems to show poor technique most readily since it’s out in the open (especially on titanium). With lugs the technique is hidden and with fillets you “finish off” your work. Ultimately you won’t see good technique if it’s there. Bad technique is hidden and good technique is invisible.
so I guess in a nutshell, unless you have access to the frame before it’s finished or painted you can’t tell the quality. The best way to guarantee top quality is to choose a builder with lots of experience. That should really narrow your choices.