To learn more about topstitching, check out my book Sewing Jeans: The complete step-by-step guide which has an extensive section on how to truly master topstitching.
I also have a topstitching tutorial blog post that has even more tips on how to master topstitching.
8 steps to perfect topstitching
1. Increase the needle tension
If you are using heavy thread this is a must
2. Use topstitching needles
3. Use regular thread in the bobbin
Domestic sewing machines usually can’t handle thick thread in the bobbin
4. Use two spools of regular thread if you don’t have heavy thread
If you only have one pin, stack two bobbins with thread on the pin.
5. Use an edge guide presser foot
Often you will topstitch close to a seam or an edge. This is where a presser foot with a center/edge guide comes in handy.
6. Pull the threads towards back when starting sewing
This will prevent the threads from getting jammed
7. Use a hump-jumper
8. Overlap with a shorter stitch length instead of back stitching
This will secure the seam without the bulk. You can also secure the threads on the reverse side with a hand sewing needle