Congratulations Rover,
Could I just recommend that you consider time in stops, in the same way as you work with the aperture ? It is very much more practical to have tests made with time doubling (or multiplied by 1,5 for half-stops) per test in order to have time/aperture equivalence, whether the paper is exposed in strips or you use the "smaller bits of paper in critical areas" approach. After you have got used to your setup, consider your printing time to be in adjusted in tenths of a stop, as that is when you can clearly see a difference (on Ilford MG anyway).
Personally, I find that the biggest aid to exposure is a contact sheet, which I always expose in a standard way - the appearance can then be the "very similar" at 10x8 size and, with a bit of practice and adjustment relative to the standard you see on your contacts, you can then get close to your final result by using just a few bits of paper in critical areas to decide on dodging or burning as Franck (?) suggested.
There are also odourless stop and fix available these days 😉
Have fun !