It is just like Nige has said. If you are trying to achieve archival results then your dilution is probably close to 1+19. A few minutes in the toning bath after being re-wet for a minute or two (if you are doing this later) or just head right to the toning batch after a short wash (3-4 mins) after the rapid fixer (this is assuming RC paper).

I usually am gaining in temperature as I move from 20 degrees C. in the developer and slowly working up to 25 degrees by the time I hit the toning bath. The reason is rapid fixer works quicker if it is warmer and I like the toning bath to be about 25 degrees otherwise the time in the bath is too long.

If you are going for an actual toning effect, then a stronger mix say 1+5 will help you. Also a longer time has a more pronounced result. RC papers do not seem to tone quite the same as fiber and the visual effect can be quite different. You will need to experiment as each type of paper reacts a bit different. The toning effect is most obvious after the print has dried. Do two identical prints, one toned and one not. Compare the results and you will see what I mean.

Kind Regards,