Tuning patterns vary from person to person, and according to maqam (musical mode or scale). Courses are always tuned in 4ths, with the lowest two courses tuned according to maqam and personal taste (not necesarily in 4ths, although some Turkish-style players are tuning their entire oud in 4ths.). These two courses are often tuned up or down one whole step depending on maqam. This poses a bit of a problem for pre-made sets, since the tension on these lower two courses must be set to perform well across the whole-step tuning variation. Generally, I'm of the opinion that it is better to choose the tension of these two courses based on the tuning used most frequently, then split the difference. This should give satisfactory results for custom sets. For pre-made sets, it's generally better to choose based on the lower tuning, so the tension will increase rather than decrease when changing the tuning.Below are common tunings:
-cc gg dd AA FF C
-cc gg dd AA GG D
-7 course Arabic Tuning: ff cc gg dd AA FF C

-dd aa ee BB AA E
-dd aa ee BB FF C