When hanging a light over a table or a kitchen island 28 to 34 inches is the recommended distance from the bottom of the light to the surface of the table or island. However the size of the light makes a difference. In general a smaller light can be moved lower and a larger light can be moved higher.
Track lighting got a bit of a bad reputation in the 1990s but when used properly it is still functional and beautiful especially for the kitchen. Pot lights aimed straight down will add general illumination but not necessarily hit the counter. An angled ceiling light on a track can put task lighting exactly where you need it. Undercabinet lighting can also achieve a similar effect. Combining both will make task lighting in the kitchen look effortless.
Instead of or in addition to sconces hidden lights can add a general glow that bounces off the wall and into the room in an even subtler and more diffuse way. Cove lights are built into niches that hide the light source (often a plain LED strip) but hidden lights can also be obscured by medicine cabinets shelving or storage units.