Make sure the grain of the wood is running in the right direction when the bowl blank is mounted on the lathe. Learn how to mount a bowl blank on a lathe in this free video on woodturning on the lathe.
We have got our bowl mounted on the lathe or our bowl blank and we are using the two prong drive spur held in between centers. This is my preferred way to mount the bowl blank on the lathe because it gives me the most flexibility to move or manipulate the bowl blank that I'm working with to make sure that I've got the grain of the bowl running in the right direction. Here let me show you what I mean. If you use this as an example, this piece of silver maple with ambrosia streakings, I use the between centers method to make sure that these striations ran evenly and uniform to give it a very pleasing appearance so this is how I do it on the lathe. I've got it mounted between centers and I'm going to back the tail stock off just a little bit and I can shift this and then spin it by hand to make sure that my grain is going to run parallel. Now I couldn't do this if I were mounting my bowl blank using a face plate or necessarily with the wood worm screw because I wouldn't be able to move the blank around and manipulate to make sure I've got my grain running parallel and I see I want to do a little bit more shifting here and I tighten my tail stock and I see that it looks good.