When you are about to sow your vegetable or flower seeds, you will find that the colour of the very small seeds, blends in with the colour of the earth. My tip is to mix the seeds with a little baking flour. You will then sow the seeds evenly in the dark soil. The result being even rows, and not over seeded.
This page contains the following solutions.
When planting seeds in the garden, an old toothbrush makes a very helpful tool. Use the end of the handle to dig little grooves for the seeds, then us the brush to gently cover the seeds with soil.
When you are handling very fine seeds for planting up. Select a dry matchbox (empty) put the seeds into it, add some silver sand (very fine sand you will buy in any gardening store). Give box a little shake, mixing seeds with sand.
An easy method for planting smaller seeds over a large area is to use a "fan" or leaf rake to disrupt the top of the soil, sprinkle the seeds over the surface of the area, and then gently re-rake to combine the loose soil with the seeds.
If you are planting very fine seeds, such as carrot, lettuce, or wildflower; mix the seeds with some colored gelatin powder. It really helps to spread the seeds evenly and makes it very easy to see where they've been sown.
Rather than bending over to plant seeds in a long garden row, consider a pipe planter. Two versions are offered on this page with the new and improved one using a length of PVC pipe and a funnel.