I don't have scraper nor rasps and use drawknife for everything. I have full control with it (lots of practice) and can do scraping while tillering by tilting blade perpendicular to wood, I can chase growth rings, I can follow basic dimensions to the line, etc.
I am happy with that, even though few rasps, spokeshave's and rat tail file for nocks would be good. But these things are all really expensive here and being a student I don't have money to invest in both the tools and auxiliary stuff needed in bow making.