I have a stitching guide that goes everywhere I go. It's called thee side of my finger.... LOL
Here Is a pic so you can see it in action.
All kidding aside I simply plant my hand on the machine in a location that is comfortable and safe, then use my finger as a guide.
Most sewing machines have guides that can be used like the edge of the foot or a mark on the deck. learning to use these natural guides will help in the long run.
Respectfully,
Al