I purchased a Simplicity pattern the first time I made anything with boning - I definitely recommend looking for costume patterns. Period pieces may be another good place to start looking, especially as the styles will be guaranteed to vary across the decades. Working with boning can be tricky if you're not an experienced seamstress, and I recommend picking up an extra needle or two just in case you slip and end up breaking one.

For me, making them wound up being too frustrating and time-consuming to be worth it, not to mention that it's really not any cheaper than buying your average mass-produced piece. If you're looking in to making something professional quality that can really cinch, then your best bet may be to email a few independent companies that make them and ask if they have any tips or sell any patterns. I know that there may very well be people on here who make professional grade corsets, but contacting the source directly would hopefully take the guesswork out of that.