I use a mouse
another thing that helps is to make your selections from paths created with the pen tool or the polygon lasso tool.
Once again anti-alias off.
You can even save paths if you like.
Another great secret when doing you initial lineart is CTRL+T that makes any selection modifiable with the freeform transform tool...this is invaluable for rims and stuff like that. You can transform your elliptical selection then stroke it then transform the same selection again...basically you can render all your ellipses on the same angle one right after the other without having to redraw each time. Note. I do the outer wheel and inner wheel on separate layers then cut away what doesn't need to be there then merge.
Your piece looks great. You have turned another corner. Very impressive.
-lemorris