If you’ve got a problem with your sewing machine such as skipping stitches and dodgy tension, the solution could be as simple as changing the needle.
Your sewing machine is an amazing piece of carefully engineered wonderfulness – a slightly blunt or even bent needle will mess up its delicate workings. Choose the right size needle for the weight of fabric, the finest being a 70 (9) and a 90 (14) for heavier fabrics.
If your sewing knits make sure you’re using a ball-point needle and leather needs a special spear-shaped leather needle.
Ideally you should have a new needle for every project.