[Michael R 1974]

msbarnes: Adams is a good book on printing. Stick with it.

Starting by adjusting exposure for detailed highlights and altering contast for the darks (as you summarized) is a good way to start. Keep it simple especially at the beginning. You can become a first class printer using simple techniques and practicing.

Ideally, with multigrade (variable contrast) papers, once you established your time with the highlights, you would not have to alter the time when switching filters to change contrast. In practice it doesn't work perfectly because the paper contrasts are not necessarily "speed matched" to the tones that produce detailed highlights. So when you change filters anywhere between 00 and 3 1/2, you might have to make some small adjustments to your exposure time. But the method you are using is good. If you move from any of those filter numbers to filter number 4 and up, yes you will probably need to make a new test print because filters 4 and up typically require a doubling of exposure.

It might seem a little strange at first but you'll get the hang of it quickly. And don't be afraid or discouraged if you have to make several test prints and work prints to get to the final result. John Sexton, one of the great printers out there, always tells students the most important tool in his darkroom is the trash can.

If the filters are above the negative, they don't have to be perfectly clean. If they are anywhere below the negative or below the lens, they need to be very clean and free of scratches.