You may want to try this method. I sprinkle a few lettuce seeds into a
container lined with damp paper towelling, put a lid on it and place in
a not too warm place, for lettuce seeds, about twentyfour hours. After
this time the seeds will have chitted and can be lifted with a pair of
tweezers and planted one to seed thingy. You will have a guaranteed
one plant per cell and no thinning. This method is particularly useful
for parsnip, as they are very erratic when it comes germination, they
can then be planted directly into the seed row, one per station, again,
a guaranteed plant per chitted seed.