I've been reading up on it, and my $80 e-bay auction chinese-knockoff special needed some attention.
I have the bass tuned BEAD and strung with 0.130-0.100-0.080-0.065 gauge nickel rounds....
the neck was nice and straight (proper relief), but I couldn't get the action any lower, due to some uneven fretwork...
finally, I bit the bullet (after months of studying techniques) and I decided to use Dan Erlewine's Bass Player Magazine method (320 grit stuck to a block with carpet tape, and a permanent marker)...
the most important part is getting the neck as straight as you possible can after you remove the strings. I used a 3" metal straight edge, ad adjusted my trussrod (strings removed), until I got the best straightness I could achieve. This took a good 10 minutes....
one I got it, I marked the top of all the frets with a marker (red shows up really well)...and then I sanded deliberately and evenly up and down, moving across the board to maintain the radius....I didn't use any pressure, just let the block slide...
It didn't take long (about 10 minutes)...when it's time to stop, you STOP...then I did what dan did in the BP article...wrapped the paper around two fingers and "skipped" the paper along up and down with really no pressure...on the strokes, you want to angle the paper so that it skips and rounds the hard edge while missing the tops of the frets (as not to lower them any more)...
this took about 5 minutes....
then I took 800 grit paper, gave another quick polish (same as the rounding method) for about 2 minutes...
all up, this took me 1/2 hour (my kids were on me about playing a game, so I had to be a bit quicker than I wanted

)...
the end result? I restrung, retightened the TR, tuned the bass, and proceeded to lower the action a WHOLE lot lower than I could before...I now have achieved medium-low action on a $80 bass
it's not perfect, I think I could have done the last few fret "fall away" a little better...but I'm more than satisfied with my first attempt....
great confidence booster for me...
the trick to doing frets, is even strokes, and a very light touch, and knowing when to stop...oh, and take your time to get the neck right first, it will make ALL the difference...
I need to get on ebay and get some more cheap basses to practice on

LOL