I got a six string fretless a while back, and I must say it has been an uphill battle to use it properly. My biggest hurdle has been figuring out how to utilize the extended range and expand my knowledge and comfort on the fretboard. Bass is not the instrument I have the most expertise on (I'm a tuba player) but I have reasonable technical facility on it. I've played four string for quite a few years now, but knowledge and mastery of the fretboard has always been a struggle since the two worlds of bass and tuba don't overlap in that area. My question is what do you people use as exercises to familiarize yourself with the entirety of the fretboard? Are there any specific things I can do that will help me through this frustrating issue I have with the six string that I want to play well so desperately? Also, what can I work on specifically to play with more fluidity so i sound better on the thing?