My absolute must have tools are my 6"x24" ruler, cutting mat, my Featherweight, my 45mm rotary cutter, my square up template ruler and plenty of quilting pins. Oh a cutting table that is the right height might be #1 most essential! Also essential are a good seam ripper, snips, good scissors, a handy pincushion, an ironing board and iron. Everything else is nice to have but could be done without.