you might check into Tim Rudman's book on toning.

There are a variety of factors that will influence "the look", paper, developer type, fixers , bleach strength, time in the bleach, strength of activator of the sepia toner, length of time in each and then the strength of the selenium and time in that selenium.
As well as which brand or formula of sepia.

For that reason, it really is helpful for you to just make a batch of prints, overprint several, at different degrees and just start practicing. Use just one brand or formula of sepia . There are already a lot of variables so keep things as simple as possible.

Keep good notes on which print has which times, etc.
Bob's suggestions are certainly a starting point.

When it comes to split toning, or toning for color shifts, the world is yours to command. Have fun, keep good records so you can repeat a process. Nothing is worst than finding something that you love and you can't remember what it was that created this effect.

That is my .02 cents worth.