A rolling carrot or onion makes knife work unnecessarily awkward. Before making small pieces, create a flat surface that can sit securely on the board.
Use a stable board on a suitable non-slip surface and keep the work area clear. Cut slowly enough to know where your fingers are. A sharp, well-maintained knife used appropriately is easier to control than a dull blade you have to force through food.
Choose the cut that the meal needs. Soup can accept rough pieces; a quick stir-fry benefits from thinner ones. There is little value in making tiny cubes if they slow you down and will be blended later.
If a task feels unsafe or physically difficult, change the ingredient preparation. Pre-cut vegetables, a suitable peeler, or a recipe using larger pieces are legitimate kitchen choices, not a failure to cook properly.