If the fabric is only sitting over the edge of the feed dogs rather than across them fully, it can get dragged down rather than fed through evenly.

• Make sure the fabric spans all of the feed dogs, not just the leading edge
• If you're sewing a narrow hem, adjust the needle position so the fabric stays supported across the feed dogs throughout

Fabric that isn't lying flat before you start, or that's being pushed or pulled during sewing, is much more likely to get caught.

• Make sure the fabric is flat and properly positioned before you begin
• Gently guide the fabric with your hands as it feeds - don't push or pull it, let the machine do the work

Too much presser foot pressure can push lightweight fabric unevenly into the feed dogs rather than guiding it smoothly through.

• If your machine allows it, reduce the presser foot pressure slightly and test on scrap
• If you're using a standard foot on a tricky fabric, switching to a different foot may also help

Fine, lightweight or slippery fabrics are the most prone to being sucked down into the machine. Giving them a bit of extra support makes a big difference.

• Place a piece of stabiliser or tissue paper underneath the fabric before sewing - this gives the feed dogs something more substantial to grip
• Tear the stabiliser away gently after sewing

For slippery, stretchy or thick fabrics a walking foot feeds the fabric from the top and bottom simultaneously, which gives you much more control and prevents uneven pulling.

• Fit a walking foot and test on scrap fabric before returning to your project
• A walking foot is particularly useful for knits, silks, velvet, and multiple thick layers

Lint and debris can stop the feed dogs from gripping fabric cleanly, making it more likely to shift or get pulled down.

• Use a small brush or vacuum attachment to clear any lint, thread bits or fabric debris from around the feed dogs
• Remove the needle plate if possible for a more thorough clean

Before returning to your project, run a few test lines on scrap fabric of the same type. Confirm the fabric feeds evenly and nothing is being pulled down into the machine.