My basic toning bleach is:
Potassium Bromide 20gm
Potassium Ferricyanide 20gm
1 Liter of water
I did this today with a print on Fomabrom IV112: develop in Dektol, water stop, plain hypofix, full wash, dilluted bleach from Foma Sepiatonder, bleached only highligts. Full wash and imersed in the toning bath, also a bit dilluted. Wash. At that stage it was a beautiful print. Creamy and shiny metallic in skies and ocean, deep black and perfect highlight. So next: 5 minutes i selenium toner. I couldnt see the shadows grew any deeper, but the highlights and mid tones became a mixture of sepia and purple. What was that? For me its not a problem for the future, i just cut after sepia toning, since shadow didnt grew any deeper in the black in selenium toner. But im curious what i did wrong and how much seleniumtoner really is going to show deeper blacks. I have seen other have great results of split-toning with sepia and selenium, and i would like to use this process.
The varients of toning effect are endless, as a difference in developer, paper, bleach dilution, toner dilution, selenium strength and difference between manufacturers products are some of those factors affecting the final look. It really is a case of trying different variations to get what you are after and keeping ordered notes on the process as you will never remember the changes you make. In short you will get through a few batches of prints before you hit on what you want and it is likely that it will happen when 'off piste', i.e not strictly following someone elses formula. Try to get to read some articles or books by Tim Rudman or Lee Frost on the subject for some inspiration.
Just as a personal example, I was toning last week when I decided to do a short bleach, around 30 seconds, followed by 30 seconds in selenium at 1:9 and then toner for around a minute, then another short bleach and another short tone all interspersed with washes: the results I stumbled into had the subtle hues I was after combined with a punchier print - a sort of 'lith-lite'. The paper I used was some old Jessops lustre finish that has now gone, so I know I will have to trial and error some different paper to get close to that again.
Tip: try to tone with a good stock of, or replenishable supply of paper.
BUT, I find it interesting and fun and the rewards are well worth the effort.
Regards, Mark Walker.