lately I've being tillering using sand paper a lot, 60 and 100 grit.
There's lot of things that I like about using this method.
first of all it makes you go slow, and this is always good when tillering, ...well maybe not for the super bowyers, but it's good for me
I've gone from the rasp than clean up with scraper, to scraper than clean up with paper, it's great you can see exactly where you're scraping if you sand it after every scraping session.
using sand paper a lot, cupping it in your hands it's easy to shape the rails ( sorry surboard talk
) I ment the corners, and using a lot the sand paper makes it really hard to get hinges or flat spots. I like the feeling of shaping with the hand rather than with a hard tool, after all the human hand is still the most flexible tool ever, unmatched so far