Bill Bolle wrote:

I normally plant two and, if both germinate, I CUT off the weakest one
after they have developed a few true leaves. Sometimes, when the
germination isn't too good, I will transplant one of the doubles into an
empty cell...




Don't be afraid to transplant things several times into larger cells.
There are very few things that don't transplant well. I generally start
things in 200 trays (200 cells per tray, slightly less than 1" square
cells). Once the roots fill the cells they will come out cleanly and
easily (water them first) and I put them into a larger cell. At that
point I can select the best ones. Cutting them off works, but you have
to be careful to cut the right one. Both methods take some work, but my
method requires more different size cells.

When planting single seeds in cells you might consider pelleted seed for
the really tiny seeds. Pelleted seed is starting to show up in home
garden catalogs and it makes it much easier to handle things like
lettuce.

PS: don't limit your seed starting to spring. some crops (like lettuce)
are best picked when they are mature and not after that. Don't just
plant one crop of lettuce or you will be eating lots of lettuce in
June/July and have none for September (or you will be eating bitter,
bolted lettuce). I plant lettuce on a weekly schedule until August
(that's probably too often for a home garden, but it provides a
continuous supply of lettuce). Lettuce will withstand remarkably low
temperatures. We can frequently pick lettuce in December in New England.
(not this year, however).