Just go for it and play easy melodies you definitely know (like movie themes from when you were a kid). That will get you playing well in tune. I used to obsessively tune trying to make sure the strings' relationships would reflect my muscle memory, but these days, the adjustments I make compensating for a slipped string has become a part of my playing.
It helps to add a little vibrato to longer notes, similar to the way that violinists and cellists do. This will mask slight inaccuracies in your finger placement.
Plug into a tuner and check yourself constantly when starting. Practise your scales and intervals with an adjacent open string droning along so you can start training your ear to instatune. Play a lot of octaves and fifths up the neck so can get used to adjusting for different positions. Practise, practise, practise.
This is all good. It always gives me a laugh when I read a post by somebody who's only been playing bass for a few months say that they picked up a fretless and had no problems playing in tune. You need to sharpen your ear as well as your fingers. Initially you'll think you're in tune, then your ear becomes more discerning and you realise your intonation isn't so hot after all .....so you improve it. Playing with a tuner is a good excercise but you don't need to worry about it doing the work of your ear. Your ear will improve too. Good luck
Great advice. There's tons of wisdom along these lines on Steve Bailey's Fretless Bass video (which I believe is out on DVD now). Also, dropping the fretted bass and sticking to the fretless for a while will definitely speed things along; play what you would usually play on the fretted bass on the fretless. This is what helped me get in tune fast (not to say that I'm perfectly in tune!).
Just play, and keep a tuner on hand at all times to check yourself. Do it all (making sure you're ALWAYS in tune) and you'll be fine.
First, learn to play in tune and AVOID vibrato. You don't want to mask inaccuracies in pitch, you want to be made miserable by them. Play arpeggios and stop at random points to check your accuracy. Play a riff and stop in the middle to compare a stopped note against an open string. Play along with a fixed-pitch instrument (keyboards are great for this). LISTEN to what you're playing. Record your practice then listen back to it with objective ears. You want your fretless playing to be so in-tune that people can't tell you're playing fretless. THEN and only then, does the fretless become part of your expression, instead of an expression of ineptitude. Listen to Freebo's playing on the first few Bonnie Raitt albums, especially stuff like "Girl, You've Been In Love Too Long" and my personal favorite "Too Long At The Fair". jte
You can try recording yourself on a fretted bass - scales, melodies, etc. - and then play it back and see if you can match it on fretless. Get some Aebersold books/CDs and play along with them. The Steve Bailey book/DVD is also good. Other than that, it really boils down to practice, practice, practice.