It really depends on the doublet in question. What kind of doublet do you have?

Some doublets can be worn with a black bow tie with little fuss (e.g., regulation doublets, "Balmoral" doublets, even Kenmore doublets).

Others (e.g., Sheriffmuir doublets, Montrose doublets) are a bit harder as they seem to be designed specifically with a jabot in mind, though I've seen them worn very well with a less formal riding stock instead.

This thread has some good discussion on the topic along with a very helpful image showing various options with a Sheriffmuir doublet that Matt Newsome was kind enough to provide.