Chris,
Cottonwood can be fabulous ... it is one of my favorite woods. It is difficult to work with because it is so soft. You CANNOT turn it without some tearout ... or voids that just occur. Cut it as smooth as possible with a sharp gouge ... at speed. Then, course grit sand paper until you've removed all the voids and tearout. After that, just go through the grits to about 400 ... making certain you have removed ALL sanding scratches, tool marks, etc.

Then ... Rub in three coats of sanding sealer, trying to rub it into the wood ...then the finish till it is dull with 400 or 600 between coats. Then ... apply 3-4 coats of deft (I use gloss) lacquer which I then polish with steel wool until smooth between coats. Finally, put renaissance wax in light amount on 0000 steel wool and polish until you have removed all spots that are not perfectly smooth. Buff with beall buffer and you are done. Sounds more complicated than it is. Renaissance wax is expensive but exquisite and one tin will do 100's of bowls.

There are lots of ways to do everything, but this consistently works for me ... every time. Putting oil on cottonwood is like trying to put oil on a cotton ball and then trying to finish it. At best, it will never be too great. I'll try to load a couple of pics.

I know that you are just starting out on this journey ... one imperfect bowl will not look like a stumbling block when you chuck up your thousandth bowl. It will just be a learning experience that you may not remember the specifics of, but will have had a learning experience that will last a lifetime. Turn another one ... if you need cottonwood, I've got plenty.

I'm not very good at this. Couldn't get a photo to load. Feel free to email me at xreiner88@live.com or some other way via the website and I'll send you some photos.