I can't believe you haven't received any replies to this - so let me be the first!
Is it possible to successfully machine-quilt using a regular domestic machine and not using a quilting foot? My machine is quite old (it's a Janome MyStyle 24) and I'm not sure that I can buy quilting accessories for it.
It's very possible to do this - I just finished my purple and yellow quilt and did the whole thing on a regular everyday machine. This link shows a picture of the process: http://www.craftster.org/forum/index.php?topic=154585.0
and I don't have a quilting foot. You just need to do lots and lots of pinning so it doesn't slip. My quilt is queen sized and I used over 125 pins ($1/50 at the dollar store.)
So what's the best method to machine quilt? Straight lines, ala "stitch in the ditch", or is it possible to do wavy lines? Not quite the same as using a free motion foot, but I'm keen to give it a try!
I have done both but I like straight lines better (but that's my personality) - when I did the wavy lines, I dropped the feed dog and did them free motion.
Also, where do you start on the quilt? I've heard you should start in the centre and work your way outwards... could somebody please give me some tips?
I think you'd get different answers from each person that answered. As I said earlier, I do most straight lines (in the ditch) and so I work from one side to the other, top to bottom or diagonal, depending on what I am stitching. If you have it well pinned, you shouldn't have to start in the middle and work out.
Hope these comments help and that others speak up with their suggestions!